Energy Efficient Renovation of Old & Historic Buildings START This project has been funded with support from the European Commission under the Lifelong Learning Programme. This publication [communication] reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein. Course description Introduction Designing a building restoration is a complex task requiring close cooperation among the architect and a group of engineers and technicians with different expertise. The focus of the modern era engineers in response to the world energy uncertainty, increasing cost and adverse effects on environment has changed toward minimizing consumption of energy in the buildings. This has imposed a big burden on the architects and engineers to change the way of their thinking. Building refurbishment Assessment & evaluation The overall energy consumption of a building is determined by many factors, some of them cannot be changed under renovation. In fact, the geometry, the orientation, the relationship between opaque and transparent surfaces, and the location in urban area represent some of the constraints to the improvement of building energy performance. In order to reduce energy consumption in existing buildings, the possibilities offered by synergistic actions on elements of the building envelope and plant components have to be assessed. Material science Modern technology Renewable energy The course deals with efficient methodologies aimed to reduce greenhouse gas mission in the building sector, developed on the basis of the different experiences regarding the building envelope, the heating systems and the use of renewable energy sources used for generation of electricity and heat/cooling. After a brief introduction to the physical fundamentals, all materials are presented in a practical way to support costeffective strategies by engineers and technicians, with the most economic advantage. The Course provides a series of solutions which allow a considerable reduction of energy consumption , with particular attention to low-cost technologies. The interventions on the building envelope should be considered in connection to the heating system improving efficiency, if possible, by means of the use of renewable energy technologies. Also, the Course provides useful basis of knowledge to support the technical and procedural choices for the energy performance renovation of old and historical buildings. Cost control 1 2 3 4 5 Go to Introduction Back Next Course description The entire Course material is divided into 6 main Modules and each module is further divided into Learning Units Introduction Module Building refurbishment Module 1: Building refurbishment Learning Unit LU1: Fundamentals & market overview Improving energy efficiency in residential buildings – the European perspectives Weatherization & energy efficiency improvement Benefits of refurbishment of existing buildings LU2: Standards of passive buildings. An overiew Chosen standards for passive buildings Fundamentals of LEED standard PHC – Passive House Certificate LU3: Conservation of historic buildings Introduction to architectural conservation Rehabilitation of historic buildings Upgrading building elements Energy efficiency and historic buildings Understanding the building before starting upgrading works Assessment & evaluation Material science Modern technology Main Topics Renewable energy Cost control 1 2 3 4 5 Go to Introduction Back Next Course description Introduction Building refurbishment Module Module 2: Assessment & evaluation Assessment & evaluation Learning Unit LU1: Comparison of standard assessment methods European standard ISO 13790 – an overview Thermal bridges – simplified calculations Refurbishment action LU2: Life-cycle energy performance evaluation Principles of life-cycle assessment in the construction sector Simplified methodology for refurbishment project Annual energy savings Calculation of life-cycle energy performance Life-cycle energy optimization LU3: Energy audit in buildings From energy audit to green audit Principles of energy audit Planning energy audit in buildings Practical advices Material science Modern technology Main Topics Renewable energy Cost control 1 2 3 4 5 Go to Introduction Back Next Course description Introduction Module Module 3: Material science Learning Unit LU1: Basics of building physics Heat & mass transport Hygrothermal behavior in buildings Ventilation & air quality Heat energy storage & cooling Thermal comfort Environmental profiling of building materials LU2: Materials for improving energy efficiency High performance insulation materials Phase change materials Materials for energy efficiency in buildings Materials skills for building refurbishment LU3: Systems & devices Opaque building envelope Transparent building envelope Shading devices Windows: nanogel & energy efficient Building refurbishment Assessment & evaluation Material science Modern technology Main Topics Renewable energy Cost control 1 2 3 4 5 Go to Introduction Back Next Course description Introduction Module Learning Unit Module 4: Modern technology LU: Modern technology systems & devices Thermal energy storage technologies Low energy cooling systems HVAC systems in energy efficient buildings Energy efficient lighting Comparative analysis of heating & cooling systems Module 5: Renewable energy systems LU: Application of RES in building retrofitting Renewable energy options Solar photovoltaic devices & systems Solar thermal devices & systems Wind energy for homes Heating pumps Micro CHP power generation Design principles for RES installations Module 6: Cost control LU: Uncertainties in investment, costs of green building, costs optimization Uncertainties & risk management Costs of green buildings Costs optimization Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Main Topics Cost control 1 2 3 4 5 Go to Introduction Back Next Introduction Introduction i Building refurbishment History In the Roman period, temples of classical Greece could often be renovated in a manner to respect eventual new functions, as well as the fashion of time. The role of the conservator as distinct from those of the restorer and the scientist had been emerging during the 1930s with a focal point in the Fogg Art Museum, Harvard University, which published the Technical Studies in the Field of the Fine Arts (1932–42). The conservation of artefacts and buildings has a long history, but the conservation as a real profession is came out from the time of foundation of the International Institute for the Conservation of Museum Objects (IIC) in 1950 and the appearance soon after in 1952 of its journal Studies in Conservation Assessment & evaluation Material science Modern technology Renewable energy Centre for the Study of the Preservation and the Restoration of Cultural Property (ICCROM), in Rome, was a further advance. The Centre was established in 1959 with the aims of advising internationally on conservation problems, coordinating conservation activators and establishing standards of training courses. Following the Second International Congress of Architects in Venice in 1964 when the Venice Charter was promulgated, the International Council of Monuments and Sites (ICOMOS) was set up in 1965 to deal with archaeological, architectural and town planning questions, to schedule monuments and sites and to monitor relevant legislation . Source: Jokilehto J. A history of architectural conservation. Oxford UK: Butterworth-Heinemann; 2009 Cost control 1 2 3 4 5 6 7 Skip Introduction Back Next Introduction i Introduction Building refurbishment Low-energy buildings in European climates should have the following features: Assessment & evaluation Material science Modern technology Excellent thermal separation and low transmission losses between the inside and outside through a highly insulated building skin High-quality glazing with U-values below at least 1.5Wm−2 K−1 and a reasonably high total energy transmittance with a g-value above 60% Heat recovery of ventilation air in winter for very high energy efficiency standards (passive building) 1 2 3 Renewable energy Cost control Applied from: Eicker U. Low energy cooling for sustainable buildings. Chichester UK: John Wiley & Sons; 2009 1 2 3 4 5 6 7 Skip Introduction Back Next Introduction Core definitions Introduction The process of applying measures necessary to sustain the all historic fabrics: existing form, integrity, and materials of an historic property. Preservation deals directly with cultural property. Its object is to keep it in its existing state. Repairs must be carried out when necessary to prevent further decay. Damage and destruction caused by water in all its forms, by chemical agents and by all types of pests and micro-organisms must be stopped in order to preserve the structure. It reflects a building’s continuum over time, through successive occupancies, and the respectful changes and alterations that are made. Assessment & evaluation Material science Modern technology Renewable energy Cost control 1 2 Rehabilitation Preservation Building refurbishment 3 4 5 6 7 The process of making possible a compatible use for a property through repair, alterations, and additions, while preserving those portions or features that convey its historical, cultural, or architectural values. The best way of preserving buildings as opposed to objects is to keep them in or modernization with or without adaptive alteration. The original use is generally the best for conservation of the fabric, as it means fewer changes. emphasizes the retention and repair of historic materials but provides more latitude than preservation because it is assumed that the property is more deteriorated prior to work. Skip Introduction Back Next Introduction Core definitions – cont. Introduction Restoration Building refurbishment The process focuses on the retention of materials, features and character of building while permitting the removal of some materials that have no impact on historic value and and reconstruction of missing features from the restoration period. Restoration and re-integration of details and features occurs frequently and is based upon respect for original material, archaeological evidence, original design and authentic documents. Replacement of missing or decayed parts must integrate with the whole building structure. Assessment & evaluation Material science Modern technology Renewable energy Reconstruction The process of depicting, by means of new construction, the form, features, and detailing of a nonsurviving building structure or object for the purpose of replicating its historic appearance. Reconstruction must be based upon accurate documentation and evidence. Cost control 1 2 3 4 5 6 7 Skip Introduction Back Next Introduction Buildings ranked in terms of energy efficiency Introduction Level Description 1 Insulated building Building refurbishment Well insulated envelope with good average thermal transmittance and maximum thermal transmittances of its parts 2 Energy efficient buildings Assessment & evaluation Good thermal insulation, correct ventilation and an opti,al use of solar and internal gains. Requirements: maximum net energy demand for heating per unit floor area, unit protected volume or unit envelope area 3 Low energy buildings Normalised energy consumption for heating, cooling, air conditioning, hot water and lighting. Calculations are based on EPDB legislation. Buildings consume less than 60 MJ/(m3 x a) primary energy for heating 4 Passive buildings Net energy demand for heating below 18 MJ/(m3 x a), good indoor climate without mechanical cooling in summer. Overall primary energy consumption does not exceed 144 MJ/(m3 x a) 5 Zero energy buildings Buildings which produce as much primary energy as is used for heating, hot water, etc. The objective is lowering primary energy consumption and producing the equivalent amount of energy from renewable sources (PV, geothermal, wind, etc) 6 Energy plus buildings Buildings produce more energy than used for various purposes 7 Energy autarkic buildings Buildings no longer depend on energy fossil fuels. Produce their own energy from renewable energy sources Material science Modern technology Renewable energy Cost control Applied from: Hens H. Applied building physics.Berlin GE: Wilhelm Ernst & Sohn; 2011 1 2 3 4 5 6 7 Skip Introduction Back Next Introduction Ethics of conservation Introduction Building refurbishment Standards of ethics for conservation work Assessment & evaluation Material science 1. The condition of the building must be recorded before any intervention 2. Historic elements must not be destroyed, falsified or removed 3. Any intervention must be the minimum necessary 4. Any intervention must be governed by unswerving respect for the aesthetic, historical and physical integrity of cultural property 5. All methods and materials used during treatment must be fully documented Modern technology Renewable energy Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003 Cost control 1 2 3 4 5 6 7 Skip Introduction Back Next Introduction Ethics of conservation Introduction Recommendations for conservation team Building refurbishment 1. Assessment & evaluation The condition of the building must be fully recorded before any intervention is begun 2. The materials and methods used during treatment must be documented Material science 3. Historic elements must not be destroyed, falsified or removed Modern technology 4. Any intervention must be the minimum necessary. It should be reversible - or at least repeatable, and not prejudice possible future interventions 5. Any intervention must be governed by unswerving respect for the aesthetic, historical and physical integrity of cultural property Renewable energy Cost control 1 2 Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003 3 4 5 6 7 Skip Introduction Back Next Module 1: Building refurbishment Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Learning objectives. To give: 1. overall critical look at energy efficiency in buildings; 2. knowledge on current standards used in energy-efficient buildings; 3. basic knowledge on important aspects of conservation of historic buildings and preservation of facades and other historic elements. Cost control Back Next Module 1: Building refurbishment LU1 Learning Unit 1: Fundamentals & market overview Introduction Building refurbishment Priorities Total energy used through the lifetime Energy used in construction work (embodied energy) Assessment & evaluation Energy used to refurbish and maintain a building Material science Energy used to run and live in the building Energy used to dispose of the building at the end of useful time Modern technology Renewable energy Cost control Draughtproof, remove leaks Insulate to high standards LU2 LU3 Buildings are responsible for 60 per cent of EU energy use, about 40–60 per cent of which is heating energy. Of the homes we will inhabit in 2050, around four out of five will be ones we inhabit now. Double or triple glaze Eliminate thermal bridges Make as airthight as possible Install passive stack ventilation with night cooling or mechanical ventilation with heat recovery Supply the reamining energy renewably where appropriate For example, Germany, Ireland, Italy, Spain and the UK together hold 100 million dwellings of which about 50 million are uninsulated. Retrofitting insulation and glazing can easily reduce heating/cooling energy use by 30–40 per cent in many buildings. With more effort, savings as high as 80 per cent can be achieved Improving energy efficiency in residential buildings – the European perspectives 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 1: Fundamentals & market overview Introduction Historic and also most of the buildings erected after World War II present poor energy performance. Building refurbishment The age of a building often has direct consequences on its conditions, not only because of the lack of services and facilities and the overall obsolescence, but also for the technological choices of the period in which it was constructed. Assessment & evaluation Material science Modern technology The improvement of the energy performance of existing buildings is one of the primary goals of the most recent European Directives, starting from 2002/91/EC Renewable energy Cost control The refurbishment of building opaque envelope represents an important approach for the reduction in global European energy consumption as prescribed by the Directive 2010/31/EU. In the non-domestic sector in Europe, building refurbishments offer far more opportunities for reducing emissions than new building; the latter represents annually less than 1.5 per cent of the building stock. The usual motivation for refurbishment includes: • replacement of degraded finishes and components; • tailoring space organization to new uses; • improving environmental quality LU1 LU2 LU3 Barriers to improve energy efficiency Lack of information about available energy efficiency options.. Financial Disincentives: The need for large up-front capital investment. Many property owners may know that they can realize substantial savings over the long run, the initial investment may be so high that they have difficulty financing it Knowledge, skill and awareness gaps: there are still quite significant knowledge and skill gaps amongst valuers when it comes to understanding the possible value impact of existing and emerging sustainability technologies Improving energy efficiency in residential buildings – the European perspectives 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 1: Fundamentals & market overview LU1 LU2 LU3 Weatherization: series of energy efficiency measures that are based on sophisticated analyses Introduction of individual homes. These analyses take the whole-house approach, which maximizes energy savings. Weatherization has become a leader in advancing home energy science and in helping spawn a new industry providing home energy efficiency services to the wider public Building refurbishment Insulation: reduces conductive heat flow Weatherization procedures include: Assessment & evaluation • Sealing bypasses – cracks, gaps, holes – around doors, windows, pipes, wirings; • Sealing air ducts using fiber reinforced mastic; • Replacing/installing dampers in exhaust ducts; • Protecting pipes from corrosion and freezing; • Installing footing drains, foundation waterproofing membrans, interior drains, etc; • Providing proper ventilation to unconditioned spaces to protect from condensation; • Installing building wrap, siding, flahing, solar tubes, skylights; • Installing insulation in walls, floors and cellings, around ducts and pipes, water heaters; • Retrofitting older windows with low-energy windows (double glazed, for instance). Material science Modern technology Renewable energy Cost control Weatherization: reduces connective heat flow Common problems include: • Poor description of building energy systems (thermal performance of the shell, electrical systems, heating and cooling systems); • Poor analysis of utility data (level of energy inefficiency); • Inadequate economic analysis (estimates of the costs of energy efficiency and renovation strategies, cost effectiveness); • Limited energy efficiency measures (often omitted data on HVAC and lighting systems); • Inadequate energy saving estimation (cost effectiveness of energy efficiency measures depends on their potential in reducing energy use. Weatherization & energy efficiency improvement 1 2 3 4 Back Next i Module 1: Building refurbishment LU1 Learning Unit 1: Fundamentals & market overview The benefits: Introduction The financial benefits of green buildings include lower energy, waste disposal, and water costs, lower environmental and emissions costs, lower operations and maintenance costs, and savings from increased productivity and health benefits. Building refurbishment Assessment & evaluation Material science Modern technology High initial costs of nearly zero-energy refurbishments (NZER) and uncertainties about the expected benefits characterize this type of investment. Other conditions of uncertainties are related to the increase in value of the building, fluctuation costs of energy, the perceived savings in the building operation and maintenance costs. Due to the seasonal variation of various climate conditions wall insulation will always bring positive benefits but in some situations may be small in comparison with the cost, or present technical difficulties or unacceptable visual impact. This is sometimes the case in historic buildings Renewable energy Cost control LU2 LU3 “Nearly any way the effects are measured, be they direct or indirect, historic preservation tends to yield significant benefits to the economy.” Randall Mason Source: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Benefits of refurbishment of existing buildings 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 2: Standards of passive buildings. An overiew LU1 LU2 LU3 BREEAM (Building Research Establishment‘s Environmental Assessment Method) is the world‘s leading and most widely used environmental assessment method for buildings, with over 115,000 buildings certified and nearly 700,000 registered. It is an integrated assessment system for construction and real estate. BREEAM is the UK Building Research Establishment Environmental Assessment Method, created in 1990. Buildings outside the United Kingdom can be assessed using BREEAM International, which is tailored to suit local circumstances Introduction Building refurbishment Major refurbishments and renovation project Minor refurbishments Assessment & evaluation is a project that results in the provision, extension or alteration of thermal elements and/or building services and fittings?. These types of projects include: - Thermal elements include walls, roofs and floors; - Fittings include windows (incl. rooflights), entrance doors; - Building services include lighting, heating and mechanical ventilation/cooling and manage- ment systems. Material science Modern technology Source: Hardy R, Tiltnes S. Technical Manual BREEAM NOR. Norwegian Green Building Council; 2012 Renewable energy This BREEAM scheme is not designed to assess a cosmetic and minor refurbishment of an existing building, i.e. works that do not result in the provision, extension or alteration of thermal elements and/or building services and fittings; or a change of use . Similar to the credit rating system in LEED, BREEAM Offices 2008 defines categories of credits according to the building impact on the environment including management, health & wellbeing, energy, transport, water, materials, waste, land use & ecology and pollution. There are up to 102 credits available. The total score percentage of an assessed building is calculated based on the credits available, number of credits achieved for each category and a weighting factor. Cost control Chosen standards - Fundamentals of BREEAM standard 1 2 3 4 5 6 Back Next i Module 1: Building refurbishment LU1 Learning Unit 2: Standards of passive buildings. An overiew Introduction LU2 LU3 The overall performance of the building is categorised as: Building refurbishment Category Assessment & evaluation Material science Modern technology Renewable energy % Unclassified < 30% Pass ≥ 30% Good ≥ 45% Very good ≥ 55% Excellent ≥ 70% Outstanding ≥ 85% For each category, there are a minimum number of credits that must be achieved Cost control Chosen standards - Fundamentals of BREEAM standard 1 2 3 4 5 6 Back Next Module 1: Building refurbishment Learning Unit 2: Standards of passive buildings. An overiew LU1 LU2 LU3 The Leadership in Energy and Environmental Design (LEED) Green Building Rating System has been developed by the United States Green Building Council (USGBC) to rate new and existing commercial, institutional, and high-rise residential buildings according to their environmental attributes and sustainable features. Introduction Building refurbishment Assessment & evaluation Unlike BREEAM, LEED is a points rather than percentage system. There are 100 base points, 6 possible Innovation in Design and 4 Regional Priority points Material science Modern technology Renewable energy Cost control Categories of LEED criteria: 1. 2. 3. 4. 5. 6. Sustainable sites; Water efficiency; Energy & atmosphere; Materials & resources; Indoor environmental quality; Innovation & design process. LEED allows the project team to choose the most effective and appropriate sustainable building measures for a given location and/or project. These “points” are then tallied to determine the appropriate level of LEED certification. Source: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003 Chosen standard - Fundamentals of LEED standard 1 2 3 4 5 6 i Back Next Module 1: Building refurbishment LU1 Learning Unit 2: Standards of passive buildings. An overiew LU2 LU3 Introduction Building refurbishment LEED rating Points Assessment & evaluation Material science Certified 40 – 49 Silver 50 – 59 Gold 60 – 79 Platinum ≥ 80 Modern technology Renewable energy Cost control Chosen standard - Fundamentals of LEED standard 1 2 3 4 5 6 Back Next Module 1: Building refurbishment LU1 Learning Unit 2: Standards of passive buildings. An overiew LU2 Passive House Standard has been shown to work for renovations by using substantial modelling to weigh up the pros and cons of different strategies. The standards allow for a great deal of flexibility. Introduction Building refurbishment LU3 i Certification criteria for non-residential buildings Assessment & evaluation Material science Modern technology Specific space heating demand Specific space heating load ≤ 15 kWh/m2a ≤ 10 W/m2 Specific useful cooling demand ≤ 15 kWh/m2a Total specific primary energy demand ≤ 120 kWh/m2a Airtightness: pressure test result, n50 ≤ 0,6 h-1 A common definition of ‘passive house renovation’ has emerged as one that improves the specific demand for heating, and cooling to a maximum of 30kWh/m2 a because it is prohibitively expensive to reach 15kWh/m2 a. Depending on the building type, energy savings vary between 80 to 95%. The specific heating demand is typically reduced from between 150 and 280kWh/m2 a to less than 30kWh/m2 a. There are many older buildings, particularly with solid walls, for which Passivhaus is not necessarily the best approach, or which will never reach anything like 80 %reduction Renewable energy Cost control i Applied from: Feist W. Certified passive house. Criteria for non-residential passive houe buildings. Darmstadt GE: Passive House Institute; 2013 Chosen standard - Fundamentals of PHC – Passive House Certificate 1 2 3 4 5 6 Back Next Module 1: Building refurbishment Learning Unit 2: Standards of passive buildings. An overiew LU1 LU2 LU3 Other standards Introduction Building refurbishment Ska Rating Ska Rating is an environmental assessment tool that assesses the sustainability of the fit-outs of office premises. The scheme is operated by the UK’s Royal Institute of Chartered Surveyors (RICS) and is thus relevant to some refurbishment projects. On completion of the assessment, a rating of Bronze, Silver or Gold may be achieved HQE HQE for ‘High Environmental Quality’ developed and mostly used in France DGNB DGNB for ‘German Sustainable Building Council’ which originated in Germany and is also used in Central and Eastern Europe Valideo Valideo a Belgian ‘sustainable construction certification system’ also used in Luxembourg Minergie Minergie, the Swiss scheme, which focuses on occupants’ comfort and energy consumption Assessment & evaluation Material science Modern technology Renewable energy Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Other standards 1 2 3 4 5 6 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Introduction What is historic building Building refurbishment Briefly, an historic building is one that gives us a sense of wonder and makes us want to know more about the people and culture that produced it. It has architectural, aesthetic, historic, documentary, archaeological, economic, social and even political and spiritual or symbolic values; but the first impact is always emotional, for it is a symbol of our cultural identity and continuity—a part of our heritage. If it has survived the hazards of 100 years of usefulness, it has a good claim to being called historic Assessment & evaluation Material science Modern technology Renewable energy The first step is to define the objective of a conservation project. The next is to identify the ‘values’ in the object, monument or site that is the cultural property in question, and to place these values in order of priority. In this way, the essential messages of the object will be respected and preserved. The values can be classified under three main headings: ‘emotional’, ‘cultural’ and ‘use’ values. Source: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003 Cost control Introduction to architectural conservation 1 2 3 4 5 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Values of historic buildings Introduction Emotional values Building refurbishment Wonder Identity Continuity Respect & veneration Symbolic & spiritual Assessment & evaluation Historic Structures ...an historic building is one that gives us a sense of wonder and makes us want to know more about the people and culture that produced it. It has architectural, aesthetic, historic, documentary, archaeological, economic, social and even political and spiritual or symbolic values; but the first impact is always emotional, for it is a symbol of our cultural identity and continuity - a part of our heritage Material science Modern technology Renewable energy Sir Bernard Feilden Cultural values Use values Documentary Historic Archeological Aesthetic Architectural Townscape Ecological Technological Scientific Functional Economic Social Educational Political Cost control Introduction to architectural conservation 1 2 3 4 5 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Introduction Direct conservation (Consolidation) Building refurbishment Consolidation is the application of adhesive or supportive materials into the actual fabric of cultural property, in order to ensure its continued durability or structural integrity. In the case of immovable cultural property, consolidation may entail the injection of adhesives to secure a detached mural painting to the wall and likewise grouting of the structure Assessment & evaluation Material science Modern technology Consolidation should be considered before application of any thermal insulations and could be used for elimination of thermal bridges by using appropriate materials (insulators) Renewable energy Cost control Introduction to architectural conservation 1 2 3 4 5 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Preparatory procedures Introduction Initial inspection Building refurbishment A preliminary visual inspection is necessary in order to define and know present condition of the building that is documented in details Documentation Assessment & evaluation Recording is essential before, during and after any intervention. In all works of preservation repair or excavation of cultural property there must always he precise documentation in the form of analytical and critical reports, illustrated with photographs and drawings Material science Degrees of intervention The minimum degree of intervention necessary and the techniques used depend upon the conditions of climate to which cultural properly is likely to be subjected. Conservation involves making interventions at various scales and levels of intensity which are determined by the physical condition and causes of deterioration. Each case must be considered as a whole, and individually, taking all factors into account Modern technology Renewable energy Treatment plan The goal of a treatment plan covers a lot of issues, from the very beginning of the project to completion, and beyond into operations and maintenance Cost control Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003. Introduction to architectural conservation 1 2 3 4 5 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Treatment plan checklist Introduction Items No Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control 1 Site survey—property boundaries, legal description, and so on 2 Documentation of the property 3 Program of the planned building use 4 List of and copies of applicable building codes 5 Survey of any hazardous materials 6 Identification of current and available utilities 7 List and copies of any restrictions on the treatment 8 List and copies of design standards that would apply, such as LEED or BREEAM rating criteria 9 List of chosen high performance insulation materials 10 List of chosen renewable energy systems 11 Characteristics of HVAC system 12 Preliminary budget 13 Preliminary schedule Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003. Introduction to architectural conservation 1 2 3 4 5 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Building a team Introduction Professionals No Building refurbishment 1 Administrator 2 Architect 3 Builder or contractor 4 Conservator 5 Civil or structural engineer 6 Energy preservation and efficiency engineer 7 Renewable energy systems expert 8 Environmental engineer 9 Materials scientist 10 Master craft worker 11 Buildings economist 12 Surveyor 13 Project manager Assessment & evaluation Material science Modern technology Renewable energy Cost control The conservation architect is the generalist in the whole building conservation process. He must have a good knowledge of all periods of architecture, combined with a thorough understanding of modern building practice; he must be able to preserve the artistic and historical value of the old structure, yet prepare schemes which are satisfactory in respect to modern requirements Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003. Introduction to architectural conservation 1 2 3 4 5 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Introduction Building refurbishment Building rehabilitation has the following social, cultural and economic advantages: Assessment & evaluation - Social, in that people and towns keep their identity; - Cultural, in that artistic, architectural, archaeological and documentary values can be preserved for their intrinsic value; - Economic, in that existing capital is used and energy is saved Material science Modern technology Renewable energy Cost control Rehabilitation of historic buildings 1 2 3 4 5 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings Introduction LU1 LU2 LU3 Flexible planning Building refurbishment Measured drawings and full investigation of the building are necessary before starting a rehabilitation project. Assessment & evaluation Material science Structural analysis of the moisture content of walls and relative humidity will possibly be necessary. Using drawings to 1/50 scale, in order to show all the existing detail, alternative schemes can be prepared Modern technology Renewable energy Cost control Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003. Rehabilitation of historic buildings 1 2 3 4 5 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Heating system Introduction Improved space heating is one of the most difficult aspects of rehabilitation Building refurbishment Heating plant factors Points that must be considered: Assessment & evaluation Building factors 1. 2. Material science 3. Modern technology 4. 5. Renewable energy Cost control Exposure, wind tightness; Heat loss – can insulation reduce this effectively? Dampness, humidity, danger to structure; Thermal mass, internal volumes, window/wall ratio; Space available for plant and fittings. 1. 2. 3. 4. Cost of fuel and labour; Size of boiler and expected life of plant and distribution system; Type of fuel and economic amount to be stored; Possible use of renewable energy. Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003. Rehabilitation of historic buildings 1 2 3 4 5 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Air conditioning Introduction The problem of large ducts and remote plant rooms required for air conditioning is difficult in existing historic buildings Building refurbishment Assessment & evaluation In order to avoid the expense of long duct runs, local plant rooms can be planned and they may have an advantage. There are many ways of manipulating heating by spraying and cooling and recirculating air in what is called air conditioning. This means that air conditioning design should be flexible, but its design depends a great deal on experience and judgement and correct briefing of the specialist engineer by the architect who knows what is needed Material science Modern technology Renewable energy Cost control Applied from: Feilden BM. Conservation of historic buildings. Oxford UK: Architectural Press, Elsevier; 2003. Rehabilitation of historic buildings 1 2 3 4 5 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Introduction Facade retention offers the following advantages: Building refurbishment Assessment & evaluation Heritage buildings often establish a specific and positive brand Retaining facades preserves often prominent buildings with public value to society and conserves craftsmanship which simply cannot be recreated today Providing the scope of refurbishment is wide, there is opportunity to improve carbon performance by replacing windows and adding insulation Preserving a historic facade and satisfying planning and conservation concerns may gain planning which can be used to allow a more expansive approach to the remainder of the building Material science Modern technology Renewable energy Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Upgrading building elements – RETENTION FACADES 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Introduction Window openings and frames establish the character of a building’s elevation Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Windows should not be altered in their proportions or details. Their frames are recessed within a wall is of historical significance and greatly affects the character of a building Replacing traditional single glazed sash windows with double glazed PVCu windows can be highly damaging to the special character and appearance of the building Where possible windows should be repaired and continue to be used Air infiltration through old windows is often excessive, so draught-proofing and weather stripping can be very effective in reducing not only heating bills but also reducing levels of noise and dust too Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Upgrading building elements - WINDOWS 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings Introduction LU1 LU2 LU3 Improving window insulation. The aim should be to improve thermal performance whilst retaining the existing windows by investigating the following options Building refurbishment Draught-proofing is the most cost-effective and least intrusive method Assessment & evaluation Material science Shutters are important features and often Modern technology contribute to the design of an elevation. Repairing and using external and internal shutters can minimise heat loss at night and reducing unwanted solar gain. Internal shutters can also be draught-proofed to improve thermal performance Renewable energy Cost control Secondary glazing improves insulation, draught-proofing and noise control. If carefully designed, it can be relatively unobtrusive (with divisions in the glazed panels hidden behind meeting rails or glazing bars). However, not all windows are suitable for secondary glazing, owing to the narrowness of the internal sill or reveals; the difficulty of accommodating the new panes within an oddly-shaped or unduly protruding architrave; or clashes with internal shutters Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Upgrading building elements - WINDOWS 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Introduction Doors which are original or of historical interest should be retained wherever possible, and repaired as necessary Building refurbishment Most external doors on historic buildings have a hardwood frames made of timber. Depending on their age and design they were usually morticed and tenoned together, either in a flat plane, or with panels fitted between stiles, and muntins and rails Assessment & evaluation Material science Modern technology Existing glazed doors should be retained, and all original or historically important glass kept. Often the easiest option to improve thermal performance will be with draught-proofing, thick insulated curtains or a draught lobby Renewable energy Cost control Thermal properties: Solid doors often have reasonable insulating properties. Most of the heat loss usually occurs by infiltration around the perimeter of the door or where gaps have developed around panels, at the junction with the door closer and through locks. Repairs and draught-proofing may be helpful Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Upgrading building elements - DOORS 1 2 3 4 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Upgrading building elements 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Introduction Building refurbishment Historic buildings display a wide range of materials and forms of construction, ranging from thick stone or earth walls, to timberframed buildings with comparatively thin and lightweight wattle-anddaub infill panels. The appearance of the external walls is usually one of the most important aspects of a historic building, while the materials give the building its unique and often local character. Other than repairs or re-pointing, they are unlikely to tolerate much change without exacerbating decay problems and detrimentally affecting their special interest and appearance Assessment & evaluation Material science Modern technology Renewable energy Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Important considerations for historic buildings Introduction The construction of many older buildings is not conducive to the retention of heat within their interior spaces. In buildings with thick masonry external walls, heat is quickly absorbed into the walls. Because of the dense masonry construction, which absorbs the heat, brick or stone buildings can take more energy to heat the internal environment Building refurbishment Assessment & evaluation Material science In buildings with thinner, solid masonry or brick walls, heat loss through the structure can be considerable, and some form of thermal upgrading will be necessary if heating costs are to be kept within reasonable limits Modern technology Renewable energy Cost control With heavy brick and stone buildings, satisfactory heating can be difficult to achieve. The heavy internal walls within the structure do have advantages: they can act as a heat store, taking in heat energy during the warm day and giving it out during the cold night. In case of heavy masonry construction, attention still needs to be given to the external envelope so that heat cannot flow straight through the building Applied from: Gorse Ch, Highfield D. Refurbishment and upgrading of buildings. New York NY: Spon Press; 2009 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Introduction Where walls need to transpire moisture and vapour effectively, new materials intended to form barriers to unwanted moisture or water vapour can impede the very processes which help a historic wall to survive in good condition Building refurbishment Assessment & evaluation Many insulation products lose their insulating qualities when wet, so moisture from damp walls or interstitial condensation can make them almost useless. Others, including some natural materials, are less affected. However, care must be taken in selecting appropriate materials that do not result in new problems such as insect infestation Material science Modern technology Many historic buildings have solid walls constructed in porous materials, with internal finishes such as lime plaster. This porosity has helped to keep many buildings in good condition Porous materials in walls Renewable energy Importance of permeability Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Introduction Wall insulation is important for: Building refurbishment heat retention in cool conditions Assessment & evaluation heat exclusion in warm conditions Material science preventing the ingress of solar gains made by the absorption of radiation on the outside of the opaque wall Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU3 External insulation Internal insulation Technical matters to consider Technical matters to consider External insulation Rain screening: Most insulation materials Detailing: Insulation will need to be carefully need to be screened from rainfall effectively detailed around the edges of window and door openings Introduction Building refurbishment LU2 Vapour build-up: If the external insulation forms a barrier to vapour, there will be a possibility of condensation build-up from internal moisture vapour within the permeable wall behind Assessment & evaluation Material science Detailing: External insulation will increase the wall thickness. This will require the design of effective details for all window and door surrounds, for roof overhangs and for the wall foot, and for junctions with adjoining construction Modern technology Warming of original fabrics: The external Renewable energy insulation will, however, offer the advantage of warming the internal fabric. This will often improve both its durability and the internal environment of the building to a useful degree Cost control Cold bridging: Breaks in all insulation layers are potential cold bridges which can lead to condensation and rot Loss of thermal mass: If a solid wall is insulated internally its thermal mass will no longer be available to moderate the internal temperature of the rooms inside Resistance to condensation: If insulation is installed internally there will be a reduction in temperature towards the outside, reaching a dew point at which internal moisture vapour will condense Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 The relative metrics and disadvantages of externally and internally applied insulation Introduction Externally applied insulation Building refurbishment Internally applied insulation Building can be almost totally wrapped in insulation, areas of cold bridging are significantly reduced Assessment & evaluation Material science Modern technology Renewable energy Cost control Cold bridging is eliminated where internal walls and floors abut the facade, further reducing heat loss and surface condensation Walls are kept warm and dry, thus increasing its insulation value and heat storage capacity Cheaper than externally applied insulation Need external scaffolding system Does not eliminate structural cold bridging In some cases it can be used to improve aesthetics Eliminates surface condensation The risk of interstitial condensation within the thickness of the wall, is reduced Can be applied selectively to various part of the buildings Walls are protected from the external environment Can produce interstitial condensation risk Can correct adverse dew point situation Reduces heat protection of outside walls Avoids disruption to or masking of existing interior wall finishes, which may have to be preserved Interstitial condensation risk with some insulants, vapour barriers must be used to prevent condensation No loss of floor space Fire risk with some insulants More expensive than internally applied insulations Practical limitations on thickness Produces similar savings in heat loss and energy consumption (up to 50%) to internally applied insulation Produces similar savings in heat loss and energy consumption (up to 50%) to externally applied insulation Applied from: Gorse Ch, Highfield D. Refurbishment and upgrading of buildings. New York NY: Spon Press; 2009 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls Introduction Solid walls constructed of bricks, stone, concrete block or in situ concrete. Other materials in historic buildings could include materials such as rammed earth (cob or adobe), and timber framed walls with solid infill of mud, clay, soil composites, often reinforced with light timber sections.These kinds of constructions often present problems for refurbishment due to damp ingress and decay Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Solutions are highly specific to the technical details of the construction, and are not dealt with here. The U-value of the noninsulated wall is of course dependent on the material and thickness of construction.Typical values range from 1.0 to 3.0,which fall a long way short of current newbuild values Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – external insulation Introduction Option 1 Rigid insulation material fixed to wall and render applied OUTSIDE Building refurbishment INSIDE Implications for external insulation solid wall Assessment & evaluation rigid insulation Material science render Modern technology Renewable energy fastening OUTSIDE Cost control All forms of external insulation can be applied without changing the thermal response of the interior. This is because the thermal mass of the structure remains coupled to the interior, which is where the gains are made (solar gains through windows or gains from internal equipment and occupants) INSIDE 1 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – external insulation Introduction Option 2 Framing fixed to wall to create voids for non-structural insulation, render applied on support OUTSIDE Building refurbishment INSIDE Implications for external insulation solid wall Assessment & evaluation External insulation also protects the structure from solar gains made on the external surface of the building. These are important considerations as both can reduce the need for air-conditioning. Finally, external insulation may be part of a treatment to provide new weatherproofing to a degraded wall. metal lath Material science render semi-grid insulation or quilt Modern technology framing Renewable energy OUTSIDE Cost control INSIDE 2 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – external insulation Introduction Option 3 As in option 2 but with rigid cladding applied (e.g. timber, metal panel) OUTSIDE Building refurbishment INSIDE Implications for external insulation solid wall Assessment & evaluation Material science In most cases, externally applied insulation eliminates cold bridges and (unlike internal insulation) does not create new cold bridges.The exception to this is where a balcony or other structure will protrude through the insulating layer. breather membrane insulation Modern technology framing Renewable energy OUTSIDE Cost control INSIDE 3 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – external insulation Introduction Option 4 Composite engineered cladding panel providing weathering and insulation OUTSIDE Building refurbishment INSIDE Implications for external insulation fastening Assessment & evaluation solid wall Material science engineered panel including insulation Modern technology This may not be easy to solve without reconstructing the attachment with a high strength, low cross section element. Non-thermal advantages include the benefit of work being able to be carried out without disturbing the interior, and possibly allowing occupation to continue. structural framing Renewable energy OUTSIDE Cost control INSIDE 4 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – external insulation Introduction i Building refurbishment External cladding may cause a major visual impact. For some historic buildings this will be unacceptable. In cases where buildings are already of rendered finish, using options 1 or 2 could leave the building with no significant change of appearance.However, applying external insulation to facades that are articulated and have openings for windows etc.,will be technically challenging. In other cases, change of appearance may be welcome, and options 3 and 4 are often used to give visual as well as thermal improvement Assessment & evaluation Material science Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – internal insulation Introduction Option 1 Rigid insulation material fixed to wall OUTSIDE Building refurbishment INSIDE rigid closed cell insulation The constructional options for internal insulation are similar in principle to external insulation Assessment & evaluation Material science Rigid insulation material fixed to wall and render or plasterboard applied. Plasterboard with integral insulation is available special fastening or adhesive Modern technology Renewable energy OUTSIDE Cost control INSIDE 1 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – internal insulation Introduction Option 2 Framing fixed to wall OUTSIDE Building refurbishment INSIDE framing Assessment & evaluation insulation Framing fixed to wall to create voids for nonstructural insulation, plasterboard or other cladding panel vapour check Material science plasterboard or other cladding panel Modern technology Renewable energy OUTSIDE Cost control INSIDE 2 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – internal insulation Introduction Interstitial condensation Building refurbishment Internally applied insulation has the potential for creating interstitial condensation – that is, condensation occurring inside the structure what can have a very damaging effect on the structure, causing corrosion and decay, and in some cases reducing the effectiveness of the insulation Assessment & evaluation The cause of interstitial condensation is that the diffusion of water vapour through the structure to a part which is at a temperature below the dewpoint of the air.The solution is prevent the vapour from diffusing through the material by applying a vapour check barrier to the warm side of the insulation Material science In practice it is difficult to ensure that the vapour check is unperforated and sealed to such as door linings and the pressure differences Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid walls – Cold bridges Introduction Cold bridges will be created where internal partitions and floors meet the external wall Building refurbishment OUTSIDE The solution is bringing the insulation back for a distance from the external wall or floor INSIDE INSIDE Assessment & evaluation heat loss through gap in insulation low surface temperature Material science paritition or floor Modern technology Renewable energy cantilevered balcony Cost control solved by insulation Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Cavity walls - construction Introduction TYPICAL CAVITY WALL CONSTRUCTION OUTSIDE INSIDE Building refurbishment Assessment & evaluation masonry cavity Material science OUTSIDE INSIDE Modern technology EXAMPLE 225mm solid wall has a U-value of 2.3W/m2°K, whilst a cavity wall with two leaves of 112mm has a U-value of 1.7W/m2°K. This is still at least five times higher than typical newbuild values Renewable energy in situ concrete external cladding Cost control Walls built from about 1950 onwards usually included a cavity. In walls of double leaf masonry (brick, concrete, stone, etc.) the main purpose of the cavity was to prevent the transmission of moisture from the outer leaf to the inner leaf. The cavity also increased the thermal resistance compared with the same amount of solid material, but not sufficiently to meet modern standards. Composite walls may have cavities inherent in their construction Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Cavity walls - construction Introduction TYPICAL CAVITY WALL CONSTRUCTION OUTSIDE INSIDE Building refurbishment Assessment & evaluation in situ concrete internal cladding Material science OUTSIDE INSIDE Modern technology If there is a cavity in the wall of the building, there is a debate about whether this should be filled or whether external or internal insulation should be applied instead. Holes in the building fabric The external wall can have cracks or tiny holes, particularly where extensions have been bolted on to the original dwelling. Inspect and repair mortar joints and fill any holes Renewable energy framed Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Cavity walls - insulation options Introduction The insulation value of the cavity is dependent on the ventilation and air movement Building refurbishment The more restricted the ventilation, the greater the insulation value, as the temperature in the cavity Assessment & evaluation The insulation value is limited by the transfer by convection and radiation of heat from one leaf to the other Material science Modern technology 1 Reducing the radiative transfer by including low-emissive surfaces 2 Reducing or eliminating convective transfer by filling the cavity with insulating material Two ways for improvement in insulation value Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Cavity walls - insulation options /practical considerations/ Introduction Masonry walls Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy In the case of double masonry walls, it is usually impractical to remove one leaf in order to place rigid insulation in the cavity.Thus the cavity can only be considered as a location for insulation if material can be injected or blown into the cavity via small openings using materials such as rockwool, glass fibre and expanded polystyrene beads, recycled cellulose fibre and vermiculite Cost control Injection of walls with loose fill is less common practice. The refurbishment of this wall type may involve the stripping of either the inner or outer leaf. Provided the cavity is large enough this will give the opportunity to fix semi-rigid insulation, still maintaining a cavity Composite & lightweight walls Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Walls - retrofit inner or outer leaf Introduction Building refurbishment During refurbishment of ancient or historic buildings there may be the need to build an inner leaf, on its own foundations, in order to provide structural support to upper floors, or to the existing external wall. If a cavity is to be included, then this could be insulated. However, it is possible that the requirements for bonding the new leaf to the existing wall may require the cavity to be too small for significant insulation to be included. In these cases, other insulation options for solid walls will have to be adopted Assessment & evaluation Material science Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - WALLS 12 13 14 15 16 17 18 19 20 21 22 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Upgrading building elements 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Floors and historic buildings Introduction The appearance of a floor can be a highly distinctive feature of a historic building. Generally floors should not be lifted. If floors have to be lifted or replaced, there are opportunities to improve insulation Building refurbishment Assessment & evaluation Material science Solid floors, such as those laid with stone, brick, early concrete, plaster or lime ash, cannot be insulated without first excavating them. Generally this should be avoided, unless it is the only way to remedy some destructive defect Damp-proof membranes will usually be incorporated. Membranes can cause more problems by driving moisture up walls and columns and are sometimes unnecessary with permeable materials Modern technology Renewable energy Cost control Upgrading building elements 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Floors and historic buildings Introduction Floorboards can often be lifted and insulation installed with comparative ease. Care should be taken if: Building refurbishment 1 Assessment & evaluation 2 The floorboards have a structural function-acting as a plate membrane in early 18th-century construction: houses have been known to collapse when all the floorboards on one level were removed at once Material science Modern technology Early wide hardwood boards (usually oak or elm) are used and cannot be lifted without causing damage to the boards or joists Renewable energy Cost control Applied from: Gorse Ch, Highfield D. Refurbishment and upgrading of buildings. New York NY: Spon Press; 2009 Upgrading building elements 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid ground floors Introduction Most solid ground floors being considered for refurbishment will be non-insulated Building refurbishment There is some uncertainty about the actual insulation value of non-insulated ground floors. It is very dependent upon the properties of the subsoil.The literature provides values ranging from 0.3 for large buildings to 1.0 for small shallow-plan buildings.The dependence on size is due to the three-dimensional nature of the heat flow.The outcome is that large buildings may have relatively low floor U-values already, and the cost benefit of floor insulation may be poorer than for other parts of the envelope Assessment & evaluation Material science Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid ground floors – insulation options Introduction Option 0 Original floor construction Building refurbishment screed Assessment & evaluation Floor insulation reduces heat losses in the heating season and may also improve comfort by reducing temperature stratification where cool air collects close to floor level.The impact of floor insulation on heat loss may be less than expected when applied to deep floor plans, due to the relatively low effective U-value of the noninsulated floor away from the perimeter Material science Modern technology slab Renewable energy soil 0 Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid ground floors – insulation options Introduction Option 1 Building refurbishment Load-bearing insulation above slab reinforced screed (5075 mm) rigid insulation (50-100mm) Load-bearing insulation above slab with reinforced screed above. This provides some insulated thermal mass, which offer some of the beneficial functions of thermal storage associated with heavyweight construction.The beneficial effects of thermal mass is realized if dense conductive materials (e.g. ceramic tiles) are used as a floor finish. For screed thickness of up to 75mm, this amount of thermal storage would be significant for 24-hour cycles only, due to its isolation from the thicker ground slab. Assessment & evaluation Material science Modern technology Renewable energy slab soil 1 Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid ground floors – insulation options Introduction Option 2 Building refurbishment Load-bearing insulation above slab with lightweight decking above timber or timber product deck rigid insulation (50-100mm) Assessment & evaluation Load-bearing insulation above slab with lightweight decking above. This behaves as a lightweight construction since the mass is isolated by the insulation.The floor finish will have little effect on thermal response Material science Modern technology Renewable energy slab soil 2 Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid ground floors – insulation options Introduction Option 3 Raised floor with rigid or non-rigid insulation Building refurbishment raised floor Raised floor with rigid or non-rigid insulation (quilt) on original floor. Raised floors are used where access to communications wiring and services are required across the whole floor.They may also be of value where underfloor voids are to be used as part of a natural ventilation system insulating quilt Assessment & evaluation Material science Modern technology Renewable energy slab soil 3 Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid ground floors – insulation options Introduction Option 4 Replaced slab with rigid insulation beneath Building refurbishment slab rigid insulation Replaced slab with rigid insulation beneath. This would only take place in major refurbishment, or in new parts of a building. It offers both high insulation and large thermal mass Assessment & evaluation Material science Modern technology Renewable energy blinding soil 4 Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Solid ground floors – underfloor heating or cooling Introduction Underfloor heating (or cooling) pipes can be incorporated in floor options 1, 2 and 4. The thermal mass of the screed in option 1 will result in a slow response emitter which could lead to control problems where rapid changes in heat loads and gains are expected. Option 4 will have a very slow response (days rather than hours), and would give control problems in all but continuously occupied buildings with very constant gains profiles Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control For option 2, the heating pipes are located just beneath the decking in the surface of the rigid insulation.This results in a rapid response emitter with a large surface area, which with suitable controls can be very efficient. Underfloor heating with option 3 could be achieved with a warm-air supply. Underfloor heating should never be installed without insulation from the ground Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Suspended ground floors Introduction Building refurbishment The insulation value of the non-insulated suspended floor is dependent on the degree of ventilation of the underfloor void. For traditional timber floors, this is often quite high and results in the U-value being significantly higher – typically around 1.5 – than for a solid floor. Reducing the ventilation rate would reduce this but would lead to high humidity and subsequent decay of the timber. For nontimber floors the void is also normally ventilated, to avoid condensation Assessment & evaluation Material science Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Suspended ground floors – insulation options Introduction Building refurbishment Option 1 Insulation placed underside of the floor pre-cast concrete or steel joists insulation option 1,2 or 3 of solid ground floors Assessment & evaluation screed If access to crawl space permits, it may be possible to apply insulation to the underside of the floor, or lay it onto the ground or oversite concrete Material science Modern technology Renewable energy insulating quilt concrete or ceramic blocks Cost control soil or oversite concrete 1 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 12 13 14 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Suspended ground floors – insulation options Introduction Option 2 Remove deck and apply rigid or semi-rigid insulation insulation option 2 of solid ground floors Building refurbishment timber or timber product deck timber joists Assessment & evaluation Remove deck and apply rigid or semi-rigid insulation between joists. Cold bridging is tolerable due to relatively high thermal resistance of timber.Thermal behaviour as lightweight Material science Modern technology Renewable energy insulation soil Cost control soil or oversite concrete 2 Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - FLOORS 12 13 14 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Gaps between floorboards Introduction Building refurbishment Assessment & evaluation Draughts from gaps between floorboards are ideally plugged where the air first gets into the building. But this is often hard without a more complete refurbishment, especially in old buildings or those with cavity walls. Beam-andblock floors may be riddled with cracks, particularly if the screed is poor Material science Modern technology Renewable energy MATERIALS: Large area boards with tongue-and-groove edges fixed on to floorboards can reduce air leakage, but you must plug all the gaps in the floorboards before laying them. If a cavity wall is filled and the problem persists, take the floorboards up, insulate between the joists and lay an airtight permeable layer above the joists before relaying the boards, taking care not to puncture the membrane except where the screws are. papier maché or sawdust mixed with dye that matches the colour of the boards, and PVA or resin; thin slices of cork from a cork board; oakum – loose hemp or jute fibre obtained by unravelling old ropes; rolls usually made from plastic Cost control Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 Upgrading building elements - FLOORS 12 13 14 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Upgrading building elements 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Roof insulation is important for two main reasons: Introduction Building refurbishment A poorly insulated roof can be a source of large heat losses due to its exposure to wind, the large convective transfer from a warm surface upwards, and high radiant losses to the night sky Assessment & evaluation Material science The roof surface receives the greatest insolation during the summer period – solar gains conducted through the roof can be a major cause of overheating and possibly expensive mitigation by air-conditioning Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Roof types in relation to opportunities for insulation Introduction A roofs with accessible attic spaces (double pitched, mono-pitched or flat) Building refurbishment Assessment & evaluation Material science Attic space Modern technology Traditional pitched Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Roof types in relation to opportunities for insulation Introduction B roofs with voids Building refurbishment Assessment & evaluation Material science Void Timber deck Modern technology Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Roof types in relation to opportunities for insulation Introduction C solid roofs Building refurbishment Assessment & evaluation Solid roof Material science Modern technology Waffle slab Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Insulating roofs with attic spaces Introduction Building refurbishment Access to the upper surface of the ceiling element allowing the placement of non-rigid insulation material. Usually there is no space limitation, large thicknesses of insulation can be accommodated and high standards of insulation achieved at low cost Assessment & evaluation Material science Care should be taken to ensure that the insulation material does not obstruct air flow at the eaves, particularly when there are no other ventilation openings Modern technology Renewable energy Migration of water vapour through celling and insulation requires ventilation of attic space Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Insulating roofs with voids Introduction Condensation creates rot Building refurbishment Access to the upper surface of the ceiling element allowing the placement of non-rigid insulation material. Usually there is no space limitation, large thicknesses of insulation can be accommodated and high standards of insulation achieved at low cost Condensation zone Timber deck Assessment & evaluation Material science Care should be taken to ensure that the insulation material does not obstruct air flow at the eaves, particularly when there are no other ventilation openings Modern technology Temperature Renewable energy Dewpoint Dewpoint profiles in insulated flat roof without vapour check and roof ventilator Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Insulating roofs with voids Introduction Ventilator Building refurbishment Filling of a roof void with particulate insulation (e.g.mineral fibre, polystyrene beads) by injection through small openings, since it would be impossible to insert an internal vapour check between the ceiling and insulation Assessment & evaluation The recommendation is to gain complete access to the void by the removal of either the inner or outer elements, and install a vapour check membrane on the warm side of the insulation Material science Modern technology Temperature Renewable energy Vapour check Dewpoint Dewpoint profiles in insulated flat roof with vapour check and roof ventilator Cost control It is strongly recommended that the void is not filled, leaving a space above the insulation that can be ventilated Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Insulating solid roofs (or with inaccessible voids) Introduction For flat roofs three options are available Building refurbishment Assessment & evaluation A Insulation above the waterproof membrane Material science B Insulation between waterproof membrane and structural deck Modern technology C Insulation below the structural deck Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Insulating solid roofs (or with inaccessible voids) Introduction A Building refurbishment Gravel or concrete tiles The so-called ‘upside-down’ roof relies on the inherent waterproof properties of closed-cell plastic or glass foam insulation Assessment & evaluation Slabs of rigid insulation are cut to fit and simply laid on the existing waterproof membrane Material science Modern technology Waterproof membrane Structure The great advantage of this method is that the waterproof membrane is protected from thermal stress and other damage, and kept at a very stable temperature. most cold bridges will be svoided Rigid insulation Renewable energy Insulation above the waterproof membrane Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Insulating solid roofs (or with inaccessible voids) Introduction B Building refurbishment This might be carried out on a roof that had to be stripped due to the poor condition of the waterproof membrane Assessment & evaluation High surface temperature The disadvantage of the method is that the waterproof membrane remains exposed to the weather Material science Modern technology Waterproof membrane (unstable temperature) Renewable energy Vapour check The only exception to this might be where on a historic building part of a flat or low-pitched roof is covered with lead or copper, and a change of appearance is unacceptable Insulation Insulation between deck and waterproof membrane Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Insulating solid roofs (or with inaccessible voids) Introduction C Temperature moderately stable Building refurbishment Assessment & evaluation The main concern is the avoidance of interstitial condensation by preventing moist air from the interior getting to the cold underside of the structural deck Material science Modern technology Vapour check Ventilation space Ceiling Insulation Renewable energy Internally insulated solid roof Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 12 13 14 15 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Surface reflectance Transmission of solar gain through non-insulated horizontal roof void (A) and effect of low emissivity surface - aluminium foil (B,C) Introduction Building refurbishment Transmitted solar gain A Assessment & evaluation Aluminium foil on upper surface Material science B Reduces emitted radiation Modern technology C Renewable energy In warm climates where solar gains through the opaque fabric of the roof are a problem, the thermal performance of a roof can be greatly influenced by increasing the reflectance of the roof surface Reflects back radiation Polished metallic surfaces also have low IR absorption. However, they have poor emissivity in the long-wave IR, thus reducing the loss of heat at night. Conventional non-metallic paints have good longwave emissivity Aluminium foil on lower surface Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Upgrading building elements - ROOFS 12 13 14 15 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Thermal upgrading of flat roofs Introduction The method used to upgrade an existing flat roof will depend to some extent on its construction. Concrete flat roofs can be upgraded only by adding the new insulation either beneath the slab at ceiling level or on top of the slab Building refurbishment Assessment & evaluation Material science With timber flat roofs, a third option is available, this being to insert the insulation within the void between the ceiling and the roof covering. It should noted that, where possible, upgrading methods that produce a ‘cold roof’ should be avoided The simplest and most costeffective means of upgrading a flat roof is to provide thermal boards at ceiling level Modern technology Renewable energy Cost control Applie from: Gorse Ch, Highfield D. Refurbishment and upgrading of buildings. New York NY: Spon Press; 2009 Upgrading building elements - ROOFS 12 13 14 15 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Thermal upgrading of pitched roofs Introduction Pitched roofs may be upgraded by inserting an additional insulating layer, either at ceiling level, or at rafter level, immediately below the roof covering Building refurbishment Assessment & evaluation Material science The new insulation may be inserted at rafter level in buildings where no ceiling exists and where the accommodation extends into the roof space. Typical examples of this include redundant churches and agricultural barns, where the existing open roof space is retained to preserve the original character Modern technology Renewable energy Cost control Insulation added at the ceiling level creates cold surfaces in the roof space. Ventilation should be used to carry condensation and water vapour outside the building. When adding insulation to create warm or cold roofs, ensure that ventilation requirements are met Applied from: Gorse Ch, Highfield D. Refurbishment and upgrading of buildings. New York NY: Spon Press; 2009 Upgrading building elements - ROOFS 12 13 14 15 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Recommended insulation standards Introduction Existing construction element Building refurbishment Typical U-value Improvement measure Target U-value Cavity walls 1,50 Fill cavity with insulation; adding additional external or internal insulation Solid walls 2,10 Insulate internally using insulation backed drylining, insulation with studwork or insulate externally with wet render, dry cladding or bespoke systems. 80-140 mm of insulation is required in all cases 0,30 Floor 0,70 Insulate above and below concrete slab or between joists of timber ground floor with 100200 mm of insulation 0,2-0,25 Modern technology Pitched roof (uninsulated) 1,90 O,16 Renewable energy Install 250-300 mm nineral wool quilt (1st layer between joists, 2nd layer across joists). Insulate between raffers with insulation in addition to 40-100 mm of insulation above or below the raffers Flat roof Add 100-160 mm of insulation above structural deck. 0,25 Assessment & evaluation Material science Cost control 1,50 0,50-0,60 0,20 Source: Energy Saving Trust CE83 Upgrading building elements 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Introduction Preservation is a better choice for long-term energy conservation Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Generally, old buildings are not insulated, they have leaky doors and windows, inefficient mechanical systems, and they don’t contain any of the new energysaving systems or equipment Cost control Energy efficiency and historic buildings 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings LU1 LU2 LU3 Introduction Opportunities to conserve energy and materials Building refurbishment employ recycled, renewable, and reused building materials Assessment & evaluation minimize waste, spillage, and misuse of building materials Material science minimize energy and water usage Modern technology provide consumer operating and maintenance information Renewable energy Cost control Applied from: Cullinane JJ. Maintaining and reparing old and historic buildings. Hoboken NJ: John Wiley & Sons; 2013 Energy efficiency and historic buildings 1 2 3 4 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings Introduction LU1 LU2 LU3 Specific goals to maximize operating efficiency Building refurbishment thermal envelope and air leakage should be monitored and improved Assessment & evaluation mechanical systems should be controllable ducts and pipes should be of minimal length and well sealed Material science use high-efficiency heating and air conditioning equipment Modern technology use high-efficiency heating and air conditioning equipment Renewable energy use energy-efficient lighting systems and maximize daylight Cost control Applied from: Cullinane JJ. Maintaining and reparing old and historic buildings. Hoboken NJ: John Wiley & Sons; 2013 Energy efficiency and historic buildings 1 2 3 4 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings Introduction i LU2 LU3 Before any modification in structure of old building you should understood it (its construction, condition and the way it performs) Building refurbishment Any alterations for energy conservation require: Assessment & evaluation Ensuring that the building is well understood, to avoid damage A Material science Modern technology B Minimising disturbance to existing fabric C Reversing the changes easily without damaging the existing fabric Renewable energy Cost control Applied from:Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings Introduction LU2 LU3 Assessment of significance i Should be done before considering any alteration Building refurbishment The actual assessment of significance is a key task in the process of upgrading historic buildings for thermal efficiency and should be carried out and documented prior to the design or preparation of any upgrading proposals Assessment & evaluation Material science Modern technology Renewable energy Cost control The following elements should be assessed Identifying the special elements External features (decorative façade, windows and doors) The spaces and internal layout ( the plan of a building is most important characteristics) Internal features (decorated plaster surfaces, panelling, floors, window shutters, doors and door-cases) Details (mouldings, stucco-work, wall and ceiling decorations) Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings Introduction i Assessment & evaluation Material science LU3 Principles of alteration A Building refurbishment LU2 B Minimum intervention Compatibility the minimum absolutely necessary alteration, the maximum historic fabric will be preserved, and thus the significance which it embodies all changes should be made using materials and techniques which are compatible with the historic fabric C Modern technology Reversibility all unavoidable changes should be made to be fully reversible ( the valuable historic fabric can be returned to its original state without damage Renewable energy Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings LU2 LU3 Building as an environmental system Introduction Building refurbishment i Assessment & evaluation It is recommended that originally-intended environmental performance of building should be researched and understood as a vital part of both its potential performance. Upgrading proposals will be naturally compatible with the existing fabric. Material science Modern technology Renewable energy Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 Building as an environmental system - cont. Building refurbishment the following issues need to be taken into consideration: Large scale Assessment & evaluation the performance of the whole building must be assessed in a holistic approach to heating, ventilation, insulation and energy efficiency Material science Modern technology Renewable energy Cost control Medium scale Smaller scale how the conditions vary from place to place around the building to make satisfactory junctions between various elements and construction details with different types and levels of insulation Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 ‘Breathability’ of buildings Building refurbishment i Assessment & evaluation Whilst ‘breathability’ may seem to be a simple matter, the actual behaviour of liquid water and water vapour, and their effects on other aspects of the performance of both the building envelope and the internal environment, can be very complex Material science Modern technology Renewable energy Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 ‘Breathability’ of buildings – cont. physical effects that should be taken into account: Building refurbishment Sources of moisture Rain, rising damp ( the capillary water ingress from ground), internal moisture vapour (condensation on cold surfaces from internal air), damaged water pipes Assessment & evaluation Hygro-thermal behaviour Expressed as relative humidity (RH), which is the amount of water vapour in air quantified as a percentage value of the total amount which air at that particular temperature could carry. It shows the potential for evaporation to take place Material science Pores & capillarity Moisture is taken up into, and evaporated from the pores in permeable materials. Water in the smallest pores is difficult to remove requiring a considerable amount of energy Modern technology Dynamic behaviour The liquid water within permeable building materials moves around in response to changing conditions (daily and seasonal cycles). The pores within the wall need not be completely filled. The moisture flows will maintain a balance between evaporation and condensation which keeps the level of moisture in the material within tolerable limits Renewable energy Permeability within the construction Permeability within the construction is important to the overall health of traditional buildings. The use of highly permeable materials allows moisture to disperse through a mixed construction Cost control Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 ‘Breathability’ of buildings – cont. physical effects that should be taken into account: Building refurbishment Latent heat Evaporation and condensation of water has effects on material temperature through the effects of latent heat Assessment & evaluation Understanding permeability The permeability of the external surfaces of traditional building materials is the most important aspect of permeability Material science NOTE: The permeability of the external surfaces of traditional building materials is the most important aspect of permeability Modern technology Internal permeability The permeability of the internal surfaces in traditional buildings has less effect on the physical health of traditional buildings Renewable energy NOTE: Permeable fabric internally has the ability to absorb quite large quantities of moisture from the internal environment, and to store it for release later NOTE: If internal humidity is adequately buffered, an interior can be comfortable for the occupants at a cooler temperature Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 ‘Breathability’ of buildings – cont. Moisture barriers Building refurbishment CAUTION: any intervention in the movement and evaporation of moisture can have significantly detrimental effects on the building fabric. The great care must be taken when considering adding modern, impermeable materials to traditional construction Assessment & evaluation Material science External moisture barriers Modern technology Rainwater can be partially absorbed and then evaporate harmlessly away but in some cases can also be trapped in large quantities over time Renewable energy NOTE: External moisture barriers effectively trap condensation from the internal environment within the building envelope Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 ‘Breathability’ of buildings – cont. Moisture barriers Building refurbishment Internal moisture barriers Assessment & evaluation Internal moisture barriers are commonly used to prevent moisture vapour from the internal environment condensing within the building fabric, particularly when insulation is being added to the internal face of solid walls Material science NOTE: Termed vapour barriers, vapour checks or vapour control layers under the right circumstances can be very effective Modern technology NOTE: Retrofitting vapour barriers into existing buildings is particularly difficult because of the existing structural connections (where floor joists are supported off internal walls) NOTE: The gaps in the vapour barriers will be at the most vulnerable point in the construction NOTE: The installation of vapour barriers into existing buildings of Renewable energy traditional construction is rarely effective, and can actually cause increased damage by concentrating the moisture rather than dispersing it Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 ‘Breathability’ of buildings – cont. Moisture barriers Building refurbishment Moisture barriers within the fabric Assessment & evaluation Moisture barriers within the construction, such as damp proof membranes (DPMs), damp proof courses (DPCs) and localised separating membranes are commonplace in converted traditional buildings Material science Traditional breathable solid ground floors have often been replaced with modern concrete constructions including a damp proof membrane. Rising damp up walls can be prevented by installing a damp proof course within them Modern technology Renewable energy NOTE: Physical most durable DPCs are difficult to insert. Injected chemical DPCs tend to have relatively short service lives Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings i Introduction LU1 LU2 ‘Breathability’ of buildings – cont. Building refurbishment Ventilation requirements Assessment & evaluation Historic buildings usually need more ventilation than modern onest, they were often more ventilated than strictly necessary because of loose-fitting doors, windows and other openings Material science LU3 If ventilation of a historic building is reduced too much, condensation, mould and fungal growth occur, leading to deterioration of the fabric Modern technology CAUTION: Great care is required in selecting an appropriate ventilation rate for a historic building Renewable energy Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 12 13 14 15 16 17 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings i Introduction LU1 LU2 LU3 Thermal bridging Building refurbishment If the thermal performance of one element is improved by adding insulation while an adjacent area is not insulated, a local cold spot – known as a thermal or cold bridge – is created Assessment & evaluation Material science NOTE: Adding more and more insulation can increase the risk of localised damp and construction failures in less-insulated components which bridge this layer. The same effect applies in case that the insulation thickness is reduced, such as at window and door reveals, and comparable construction details Modern technology Renewable energy Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 12 13 14 15 16 17 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction Building refurbishment LU2 LU3 Material compatibility All interventions to upgrade the energy efficiency of historic buildings must be technically compatible with the existing structure. It is important that technical risks are not introduced Assessment & evaluation NOTE: It is best practice to use materials which match the original fabric as Material science closely as possible NOTE: It is important to ensure that new materials have permeability which is Modern technology appropriate to the existing breathable construction to which they are being added CAUTION: To use of modern substitutes and to introduce impermeable materials or membranes into permeable traditional construction is not good practice and can lead to trouble Renewable energy Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 12 13 14 15 16 17 Back Next Module 1: Building refurbishment Learning Unit 3: Conservation of historic buildings i Introduction LU1 LU2 LU3 Material compatibility Building refurbishment Natural insulation materials Assessment & evaluation In case of historic buildings, the use of insulation materials based on natural fibres can be very beneficial. (wool, hemp, flax, recycled newspaper). Fibres are able to absorb and then release moisture by evaporation. Synthetic insulation materials often do not have these attribute (glass fibre, rock wool) Material science Modern technology Renewable energy Cost control Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 12 13 14 15 16 17 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction Material science Modern technology LU3 Establishing existing performance Before carrying out any upgrading works it is necessary to establish how well the building is performing so improvements can be targeted to those areas where the biggest return can be made with the minimum risk. The following non-destructive tests give useful information to help guide proposals for upgrading the energy efficiency of traditional buildings: Building refurbishment Assessment & evaluation LU2 Air pressurisation testing Infra-red thermography Dampness measurement This process uses a fan set temporarily into a doorway of the building to measure how much air is escaping. It gives a very useful information about the overall degree of air infiltration that a building suffers from Survey of the external envelope of a building using an infra-red camera, and gives a visual indication of where heat may be escaping from Dampness can be measured in a range of ways by specialists, the removal of small samples will be required for accuracy Renewable energy Cost control In-Situ U-Value measurement Borescope/CCTV Valuable technique for assessing the actual thermal performance of building elements.It should be carried out in the winter. The Uvalues resulting are not necessarily comparable with those obtained by conventional calculation methods, but is more accurate in many cases Visual techniques for examining small voids within structures, flues and drains. Very useful and cost-effective ways of assessing whether damage has occurred in hidden areas of a construction, and whether upgrading is likely to be possible NOTE: Electrical dampness meters should not be used on masonry or plasterwork, because of extremely misleading readings Applied from: Westergaard M. Energy efficiency and historic buildings. London UK: English Heritage; 2010 Understanding the building before starting upgrading works 12 13 14 15 16 17 Back Next Module 1: Building refurbishment LU1 Learning Unit 3: Conservation of historic buildings i Introduction LU2 LU3 Establishing existing performance Obtaining energy performance data Building refurbishment The parameters to be monitored include: Assessment & evaluation external air temperature, Detailed performance data can be obtained from instrumental monitoring of the building, in which key parameters are measured in regular time intervals (between five and fifteen minutes) Material science Modern technology solar radiation, internal air temperatures, sub-metered energy for heating, cooling, ventilation, lighting, plug loads,etc. relative humidity of the outside and inside air (if the building uses comfort cooling) Renewable energy Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Understanding the building before starting upgrading works 12 13 14 15 16 17 Back Next Module 2: Assessment & evaluation Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Learning objectives. To give: 1. basic knowledge and understanding of assessment methods commonly used in Europe (European Standard ISO 13790, an overview, thermal bridges-simplified calculations, refurbishment action); 2. basic knowledge on evaluation of energy performance in time and its importance for refurbishment processes (principles of life cycle assessment, simplified methodology for refurbishment project, annual energy savings-calculation, life cycle energy optimization); 3. basic knowledge on energy audit in buildings (principles of energy audit, basic calculations of energy loses, planning energy audit in buildings, practical advices). Cost control Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods Introduction EN ISO 13790 (Energy performance of buildings— Calculation of energy use for spaces—heating and cooling) provides indications and rules on the calculation methods for the design and evaluation of thermal and energy performance of buildings Building refurbishment Assessment & evaluation Material science LU2 LU3 evaluating compliance with regulations and laws P U R P O S E S comparing the energy performance of various design alternatives for a building energy certification of buildings assessing the effect of possible refurbishment measures on existing buildings Basic methods Modern technology Renewable energy Cost control Quasi steady-state Dynamic calculating the heat balance over one month or the whole season, taking into account dynamic effects by the simplified determination of a gain utilization factor calculating the heat balance over 1 h and taking into account the heat stored and released from the mass of the building in a detailed way Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 European standard ISO 13790 – an overview 1 2 3 4 5 6 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Definition and overview Introduction Classification Definition Building refurbishment Thermal bridge is defined as part of the building envelope, where t he uniform thermal resistance is significantly changed by full or partial penetration of the building envelope by materials with a different thermal conductivity, change in thickness of the fabric, or a difference between internal and external areas, such as occur at wall/floor/ceiling junctions (EN ISO 10211 Standard) Assessment & evaluation Material science Modern technology Repeating Non-repeating where they follow a regular pattern, e.g., wall ties penetrating a cavity wall e.g. a single lintel crossing a cavity wall Geometrical at the junction of two planes, e.g., the corners of walls, or wall/ceiling junctions Renewable energy Cost control Thermal bridges – definition & overview 1 2 3 4 5 6 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Types of thermal bridges Introduction Geometric thermal bridges Building refurbishment A consequence of the three dimensional character of a building: angles and corners, inner and outer reveals around windows, etc Assessment & evaluation Material science Structural thermal bridges Modern technology The consequence of structural decisions. Examples: steel or concrete girders and columns that penetrate the envelope, discontinuities in the thermal insulation. Structural thermal bridges could be there for reasons of structural integrity Renewable energy Cost control Applied from: Hens H. Building physics – heat, air and moisture. Berlin GE: Ernst & Sohn Verlag; 2007 Thermal bridges – types 1 2 3 4 5 6 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Rules to follow: Introduction Structural thermal bridges Geometric thermal bridges Building refurbishment Neutralize geometric thermal bridges by assuring continuity of the thermal insulation Assessment & evaluation Material science Modern technology Avoid structural thermal bridges by paying attention to continuity of the insulation layer. It should be possible to go around the building drawings with a tracer in the insulation, without crossing any element that forms an easy path for heat between the inside and the outside Renewable energy Cost control Applied from: Hens H. Building physics – heat, air and moisture. Berlin GE: Ernst & Sohn Verlag; 2007 Thermal bridges – rules to follow 1 2 3 4 5 6 Back Next Module 2: Assessment & evaluation Learning Unit 1: Comparison of standard assessment methods LU1 LU2 LU3 Thermal bridges evaluation Introduction Building refurbishment The linear thermal transmittance w [W/(m K)] is used for calculation of the whole heat flow. It represents the heat flow rate in steady-state conditions, divided by the length of the junction and by the temperature difference between internal and external surfaces Assessment & evaluation Material science EN ISO 14683 gives reference values for some standard structures referring to a catalogue of thermal bridges and values of ‘w’ in relation to some different geometrical dimension The EN ISO 10211 Standard provides for the definition of a geometrical model of a thermal bridge for the numerical calculation of heat flows and surface temperatures considering the following assumptions: Modern technology 1. all physical properties are independent from temperature; 2. there are no heat sources within the building element Renewable energy Cost control Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Thermal bridges – evaluation 1 2 3 4 5 6 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Thermal bridges evaluation Introduction In case of old existing buildings, if detailed information about thermal bridges is not available, EN ISO 13790 allows us to evaluate their influence in a simplified way, as a percentage increase in the wall thermal transmittance Building refurbishment Assessment & evaluation Material science simplified calculation requires the determination of the length and the linear thermal transmittance for each twodimensional joint, applying ISO 14683 (analytical method) the incidence of thermal bridges is evaluated by increasing the thermal transmittance of the wall by a percentage adjustment coefficient, which depends on wall typology Renewable energy Cost control calculations allow to verify all the possible solutions for structural linkages and to provide a more accurate energy model of buildings it is possible to obtain an underestimation of their influence, which can be more significant as much as the building is insulated, and it could bring to obtain a more efficient energy class than the real one NOTE NOTE Modern technology analytical calculation Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Thermal bridges – evaluation 1 2 3 4 5 6 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Introduction 1 Building refurbishment 2 Project team Assessment & evaluation Material science 3 4 Developer (money) Architect (design) NOTE MEP engineers (mechanical, electrical and plumbing 5 Modern technology Project manager Expert in historic preservation 6 Renewable energy Expert in energy conservation 7 Cost control Expert in renewable energy systems The most important element in developing and undertaking a treatment plan for an old or historic building is communication—ensuring that each member of the project team understands the basis on which the work will be done and the goals of the project Applied from: Cullinane JJ. Maintaining and reparing old and historic buildings. Hoboken NJ: John Wiley & Sons; 2013 Refurbishment action – developing the plan 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Developing the plan - 9 steps Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Step 1 Assemble all of the survey data and documentation Step 2 Identify the significance of the property and its contributing elements Step 3 Identify the use of the property Step 4 Identify the design parameters and limitations Step 5 Determine the primary treatment—preservation, rehabilitation, restoration, or reconstruction Step 6 Identify changes that would be required to meet program needs, code compliance, and standards Step 7 Evaluate the effect of the changes on the significance and fabric of the property. (For historic buildings they would be defined as “No Effect,” “No Adverse Effect,” or “Adverse Effect.” Step 8 Identify the primary issues that will affect treatment of the property— structural, systems failure, deterioration of materials, building function, accessibility, security, energy conservation, budget, schedule, and reviews Step 9 Initiate design Applied from: Cullinane JJ. Maintaining and reparing old and historic buildings. Hoboken NJ: John Wiley & Sons; 2013 Refurbishment action – developing the plan - steps 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods Simplified energy balance for building during heating season Introduction Thermal gains Building refurbishment Thermal Losses Renewable sources Envelope Assessment & evaluation Opaque walls Solar gains Material science Windows Building Roofs Internal gains LU2 LU3 The thermal losses from the envelope increase as the outside temperature decreases, with a dependency upon the values of the thermal resistance of the individual building components Better insulation, increasing the thermal resistance to the passage of heat, therefore helps to reduce heat losses Basements Modern technology Ventilation Renewable energy Heating system Cost control The global energy losses for heating are the sum of the losses due to thermal dispersions through the envelope and the losses due to ventilation of spaces Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – energy balance 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Airtightness Introduction Air barrier can be defined as one with a maximum air permanence of 0.05m3/h/m2 at 50Pa. Airtightness barrier must form a continuous envelope around the structure within the insulation. This is easier if Gaps of you are renovating the whole various building widths were then made in the vapour Intelligent membrans barrier affect airtightness Airtight membranes with variable Measuring airtightness Building refurbishment ‘Air changes per hour’ at the artificially induced pressure of 50 Pa is the accepted metric for measuring airtightness Assessment & evaluation Measuring airtightness Material science The rate of air leakage is in terms of whole building permeability, or the volume of air leaking per hour per square metre (m3/h/m2) of total surface area (ceiling area + wall area + floor area) at 50 Pa Modern technology Renewable energy vapour resistance. They are able to resist vapour migrating into structural elements. Membrans can be used in combination with ventilation Installers must strive for the total elimination of gaps Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – airtightness 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Cavity wall insulation Introduction Insulation procedure Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control 1 installers should survey the cavity, and proceed only if the wall meets standards 2 injection holes are drilled through the mortar joints at 1m intervals 3 barriers are installed to prevent the fill entering next door’s cavities 4 air ventilators that cross the cavity are sleeved (or sealed, if obsolete) 5 the insulant is injected 6 quality checks are carried out 7 the holes are filled with colour-matched mortar/render Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – cavity wall insulation 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Cavity wall insulation Introduction Problems with cavity wall insulation Building refurbishment internal condensation caused by gaps in the insulation Assessment & evaluation Material science Modern technology damp in geographical areas where the wall faces driving rain increased corrosion of wall ties Cavity walls not suitable for insulation can be treated as solid walls Renewable energy Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – cavity wall insulation 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 External wall insulation External wall insulation involves applying an insulating layer and a decorative weatherproof finish to the outside wall of a building. The aim is to reach U-values of below 0.30W/m2K (half of this for Passivhaus standard) Introduction Systems available Building refurbishment Assessment & evaluation Material science Wet render systems Dry cladding systems Traditional and polymer-modified cementitious render can be used in low-rise and high-rise applications. Polymer helps make the render more workable on site and gives weather protection and flexibility The insulant may be independently fixed to the substrate with a mechanical or adhesive fixing, or partially retained by the framework (treated timber, steel or aluminium) System includes: insulant; adhesive mortar, mechanical fixings; profiles and edgings used on corners, a base-coat render; a top-coat render, with or without a finish Modern technology Renewable energy They are cheaper than dry cladding CAUTION: quality is variable Cost control System includes: insulant, fixed to the substrate similar to wet render system; a supporting framework or cladding fixing system; ventilated cavity; cladding material and fixings Most systems incorporate a ventilation cavity between the cladding and the insulation to ensure that any penetrating moisture is carried away Bespoke systems Designed for individual projects and tend to have simple detailing, allowing a non-specialist to construct them. A typical design may consist of a rainscreen fastened onto a substrate such as single blockwork with timber framing. Timber studwork and a sheathing material create a 250mm cavity filled with loose cellulose insulation Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – external wall insulation 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Internal insulation Introduction Techniques used for internal insulation Building refurbishment Assessment & evaluation Insulated plasterboard thermal boards glued directly on to the internal walls. There must be absolutely no gaps between the boards. Leave a small cavity between the internal wall surface and the insulation. Some even recommend spreading adhesive over the entire surface area to eliminate the possibility of any air movement Studs they are employed on a wall that has previously suffered from damp. Create a cavity between the internal wall surface and the insulation. Studwork is good where the wall is bowed or uneven and space is not at a premium Material science Modern technology Renewable energy Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – internal insulation 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Roof insulation Introduction Building refurbishment loft loft insulation insulation Assessment & evaluation internal internal roof roof insulation insulation Roof insulation includes Material science Modern technology flat roof insulation external roof insulation Renewable energy Cost control NOTE: In all cases, before work begins, inspect timbers for damage and repair if necessary Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – roof insulation 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 1: Comparison of standard assessment methods LU2 LU3 Floor insulation Introduction Building refurbishment Heat loss through exposed floors can be reduced by up to 60 per cent but much depends on their size and shape, the type of floor and the conductivity of the ground below it Assessment & evaluation Material science Modern technology Heat loss is greatest around the edges Renewable energy Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – floor insulation 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation Learning Unit 1: Comparison of standard assessment methods LU1 LU2 LU3 Floor insulation Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Aim for an R-value of 2.5m2K/W; this will generally achieve a U-value between 0.20 and 0.25W/m2K. Ideally, a concrete floor with no insulation and damp-proof membrane beneath it should be taken up and the whole job started afresh Solid concrete floors Where this is not possible, the only choice is to install insulation and a new deck on top, but the higher floor is likely to cause problems at stairs and door thresholds. You need a minimum 60mm layer of phenolic, polyisocyanurate or polyurethane foam insulant; 200mm would be perfect Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – floor insulation 12 13 Back Next Module 2: Assessment & evaluation Learning Unit 1: Comparison of standard assessment methods LU1 LU2 LU3 Floor insulation Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Aim for an R-value of 3.5m2K/W; this will generally achieve a U-value between 0.20 and 0.25W/m2K. Use mineral wool or rigid insulating boards. It should fill the space between the joists and be the full depth of the joist. If there is a cellar or basement, insulation under the ground floor might be installed from below. Fit the insulation tight up to the underside of the floor but not over-compressed Suspended timber floors CAUTION: Do not install a vapour control layer – it can trap spilt water. Ensure the under-floor void is well ventilated Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Refurbishment action – floor insulation 12 13 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Definition Introduction i Building refurbishment A technique aiming at the assessment of hazards for the environment connected with products or services, both by identification and quantitative evaluation of the consumed materials and energy, wastes and assessment of the effect of materials, energy and wastes on the environment Assessment & evaluation Material science i Modern technology Renewable energy Cost control Assessment concerns the full cycle of life of the product or service, starting with extracting and processing of mineral raw materials, the production process of goods, distribution, consumption, secondary utilisation and final decommissioning and transport Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of life-cycle assessment in the construction sector 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Hazards affecting the environment Introduction Building refurbishment Assessment & evaluation effect on the quality of ecosystems (contamination, disposal of wastes) Material science effect on human health (occupational diseases, safety of work) Modern technology depletion of natural resources involving (degradation of sites) Renewable energy Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of life-cycle assessment in the construction sector 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Lifecycle of a product or service Introduction Building refurbishment Gathering of raw materials Assessment & evaluation Exploitation Processing of raw materials Material science Manufacturing Recovering Modern technology Disposal Renewable energy Recycling Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of life-cycle assessment in the construction sector 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Stages of LCA Introduction Building refurbishment Assessment & evaluation Definition of the goal and scope Inventory analysis Impact assessment Interpretation 1 2 3 4 Determine the exact details of the boundaries and level of the analysis. The boundaries define the set of unit processes included in the analysis. The unit process is a smallest part of the system of the product for which the input data are gathered Material science Modern technology Renewable energy The following data are gathered for each unit process: • data on the amount of supplied energy and materials, • information concerning amount of wastes, • the amount of noxious contaminating emissions The input and output quantities should refer to the functional unit 1 Cost control 2 Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of life-cycle assessment in the construction sector 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Stages of LCA cont. Introduction Building refurbishment Assessment & evaluation Material science Definition of the goal and scope Inventory analysis Impact assessment Interpretation 1 2 3 4 ◊ Identification of the main factors influencing the given category of effects; ◊ Assessment of the credibility of the achieved results; ◊ The completeness of information is checked, and the sensitivity and uncertainty are analyzed; ◊ Evaluation of the LCA report by independent experts 4 Assessment of the effect of the input and output fluxes. The index of the given category of effect on the environment is calculated Modern technology Renewable energy 3 Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of life-cycle assessment in the construction sector 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Input and output flows of materials, energy and pollutants from a life cycle perspective Introduction Building refurbishment input Assessment & evaluation Raw material extraction Manufacturing Materials Material science Emissions Distribution/transport Energy Wastes Use & maintenance Modern technology Disposal & recycling output Renewable energy Cost control Adopted from: Torgal-Pacheco F, et al. Eco-efficient construction and building materials. Cambridge UK: Woodhead Publishing Ltd.; 2014 Principles of life-cycle assessment in the construction sector 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Introduction Building refurbishment Simplified methodology can facilitate life cycle energy performance evaluation, through the combination of embodied energy data for products with energy assessment tools already applied for the use stage of the buildings Assessment & evaluation Material science The embodied energy of the products means all energy inputs to a product, expressed in primary energy, from extraction to manufacturing, until the product leaves the factory gate Full life cycle energy performance evaluation also include transport to the building site, construction processes and the ‘end of life’ part of the life cycle, considering demolition and recycling potential or landfill Modern technology Renewable energy Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Simplified methodology for refurbishment project 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation Introduction Assessment & evaluation LU3 Annual energy savingscalculation rules Energy use calculations have evolved from steadystate heat loss and semi-static monthly energy demand calculations to complex dynamic energy performance simulation tools which can model annual energy use over very short intervals (hours, minutes, even to a fraction of a second) Building refurbishment LU2 International standards such as EN ISO 13790 ‘Energy performance of buildings—Calculation of energy use for space heating and cooling’, which include monthly calculation methodologies, are considered of sufficient accuracy for application in energy certification. Factors such as plug-in loads and equipment are generally excluded in some calculation methods, particularly in energy rating and certification methods Material science Modern technology In refurbishment projects, and particularly if the typology and pattern of use of the building are not expected to change after refurbishment, it is generally good practice to analyse historical energy use in the building to more accurately estimate potential energy savings Renewable energy Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Annual energy savings 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Introduction Step 1 Building refurbishment Studied Refurbishment Project OCCUPANCY LOCATION Assessment & evaluation Energy performance assessment Annual energy savings Step 3 Life cycle energy performance Existing & refurbishment scenario Material science (materials, energy systems, etc) Refurbishment products & systems Modern technology Embodied energy data Annualized embodied energy Lifetime database or estimation Step 2 Renewable energy Flow diagram of proposed methodology for life cycle energy performance evaluation of refurbishment projects Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Calculation of life-cycle energy performance 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control From a life cycle energy perspective, the annual energy savings of a building refurbishment project must only be taken into account after the embodied energy of added building components and systems is subtracted In building refurbishment projects the impact of the building materials can be discounted to the expected energy savings from the refurbishment project. The life cycle energy performance of the refurbishment project will consider both the energy savings and the embodied energy The AEE (added embodied energy) is always above zero in a refurbishment project when we need to add new products and systems, but ideally the added embodied energy should be as low as possible to ensure that large life cycle energy savings are achieved When we refurbish a building towards ‘zero-energy’ use in operation, or even to be an ‘energy-positive’ building, this requires the installation of some form of renewable energy systems Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Calculation of life-cycle energy performance 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 2: Life-cycle energy performance evaluation LU2 LU3 To support practitioners willing to consider building energy refurbishment projects from a life cycle perspective and use it as an input for the design, the concept of ‘NER’ can be introduced Introduction Building refurbishment NER indicator, frequently used in the renewable energy field, sometimes also called Energy Return of Investment, Energy Returned on Energy Invested or Energy Yield Ratio, can be represented for the refurbishment of an existing building through the following formula: Assessment & evaluation Material science Modern technology 𝑁𝐸𝑅 = Renewable energy 𝐴𝐸𝑈1 − 𝐴𝐸𝑈2 𝐴𝐸𝐸2 − 𝐴𝐸𝐸1 where: AEU – Annual Energy Use AEE- Annualized Embodied Energy Cost control The NER can be defined for building refurbishment as the ratio of the decrease in annual energy use (annual energy savings) to the increase in AEE. This ratio can be used to compare refurbishment options for improving energy performance in use: the higher the NER of a particular refurbishment strategy, the more effective it will be in delivering life cycle energy savings All options where the NER is greater than one will contribute to an improvement in life cycle energy performance, an energy saved over the life cycle. The higher the NER of a refurbishment strategy, the larger the life cycle energy savings Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Life-cycle energy optimization 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation Learning Unit 2: Life-cycle energy performance evaluation Assessment & evaluation Material science Modern technology Renewable energy Cost control LU2 LU3 EXAMPLE Introduction Building refurbishment LU1 The first layer of insulation in a typical existing house would normally yield very high NER, as would save a large amount of energy with a small amount of material. Subsequent layers of insulation, while adding to the total embodied energy, would not deliver an equivalent energy saving, and so a refurbishment of a building envelope would represent a diminishing NER as we increase the insulation thickness Technologies such as solar water or space heating systems would also generally represent a diminishing NER with the size of the installation, as the annual solar input rate per square metre of installation decreases at constant heat demand, once we have surpassed the summer base load with the summer solar input This frequently occurs with large solar installations, which are in practice oversized for the summer, and progressive increases in collector sizes do increase embodied energy but not proportionally increase the solar energy input. Technologies such as PV, however, will have a practically constant NER independent of their size as the production of electricity will be proportional to the quantity of materials used in their production and installation Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Life-cycle energy optimization 12 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Introduction Definition of energy audit Building refurbishment The definition provided in the Standard EN 16247-1:20122, defines the energy audit as ‘‘a systematic procedure to obtain an adequate knowledge of the profiles of energy consumption of an existing building or group of buildings, an industrial and service private or public, in order to identify and quantify in terms of cost effectiveness of energy saving opportunities and the relationship of what is revealed’’ Assessment & evaluation Material science Modern technology Renewable energy Cost control Principles of energy audit – types of energy audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Walkthrough audit Introduction The main purpose of a walkthrough audit is to provide recommendations for improving the energy efficiency of the residence by investigating selected operating and maintenance measures (O&Ms) and energy efficiency measures (EEMs) with short payback periods Building refurbishment Assessment & evaluation Material science Walkthrough audit allows the collection of basic information about the building envelope (windows, walls, and doors), and the lighting fixtures, appliances, and heating and cooling systems. The auditor should meet and talk to the building owners and occupants to determine any problematic areas of the building related to thermal comfort and energy performance This audit consists of a short onsite visit of the facility to identify areas where simple and inexpensive actions can provide immediate energy use or operating cost savings Modern technology Renewable energy Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of energy audit – types of energy audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Standard energy audit (SEA) Introduction The standard audit provides a comprehensive energy analysis for the energy systems of the facility. It includes the development of a baseline for the energy use of the facility and the evaluation of the energy savings and the cost-effectiveness of appropriately selected energy conservation measures Building refurbishment Assessment & evaluation Material science Simplified tools are used to develop baseline energy models and to predict the energy savings of energy conservation measures. The standard energy audit includes a walkthrough energy audit, a utility data analysis, a detailed energy modeling analysis, and an economic analysis to recommend cost-effective energy efficiency measures Standard audit may involve some “spot measurement” of parameters such as motor power, space temperature and relative humidity, and airflow rates, where necessary. It is useful exercises to be carried out before a detailed study so that the resources available for the detailed study can be better utilized Modern technology Renewable energy Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of energy audit – types of energy audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Detailed energy audit (DEA) Introduction In the detailed energy audit, more rigorous economical evaluation of the energy conservation measures is generally performed. Specifically, the cost-effectiveness of energy retrofits may be determined based on the life cycle cost (LCC) analysis rather than the simple payback period analysis. LCC analysis takes into account a number of economic parameters, such as interest, inflation, and tax rates Building refurbishment Assessment & evaluation Material science DEA focuses on potential optimization and capital intensive projects identified or short-listed during Standard Energy Audits and involve more detailed field data gathering and engineering analysis. They also provide detailed project cost and savings information with a high level of confidence, sufficient for major capital investment decisions. It is sometimes called investment grade audits (IGA) DEA includes the following tasks: 1. Introductory meeting. Kick off meeting with the facility management team 2. Audit interviews: to meet the relevant people to gather accurate information. 3. Data collection and logging - is the most important part of the detailed study, where data on equipment and operations is collected Modern technology Renewable energy Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of energy audit – types of energy audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Energy audits and energy certification, an integrated approach Introduction Walkthrough audit Building refurbishment Consistent conditions YES Assessment & evaluation Check NO Complex building Material science YES Check Modern technology NO Standard audit Simulation audit Retrofit measures implementation Renewable energy Energy certification Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Principles of energy audit – types of energy audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Auditor decides what are the measures to be proposed, assesses the costs and checks the benefits Introduction Building refurbishment Green Energy Audit Report should contain the following information: Assessment & evaluation analysis of the current situation definition of the baseline Material science description of the proposed retrofit measures economic evaluations of these retrofit measures Modern technology environmental assessments of these retrofit measures definition of the management and maintenance plan Renewable energy Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Planning green energy audit in buildings 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Reporting for Walkthrough Audit Introduction Building refurbishment Assessment & evaluation 1 Renewable energy Describe the basic energy systems of the building, including building envelope, mechanical systems, and electrical systems 2 Perform basic testing and measurements to assess the basic performance of various energy systems 3 Identify some potential operation and maintenance (O&M) measures and energy conservation measures (ECMs) as well as any measures required to improve comfort problems Material science Modern technology Sections of the final Report Tasks to do: 4 Evaluate the energy savings (or requirements if measures are needed to improve comfort) using simplified analysis methods 1 Legible and complete drawings showing the floor plan and at least two elevation views 2 A brief description of the architectural features and energy systems of the building 3 A description of any testing procedures or measurements 4 A discussion of the walkthrough audit tasks and its outcome 5 A description of the calculation details to estimate energy use and cost savings 6 A summary of the energy and economic analysis results 7 Some photos to highlight some of the features and the problem areas of the house walkthrough audit can be a stand-alone task or part of a standard energy audit Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Practical advices – reporting for Walkthrough Audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Reporting for Standard Audit Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Sections of the final Report Tasks to do: 1 Carry out a detailed survey of lighting and electrical equipment 1 Legible and complete drawings showing the floor plan and at least two elevation views 2 Identify HVAC systems and their operation schedules 2 A brief description of the features of the building and its systems 3 Perform any relevant measurements, such as lighting levels, thermal images, airflow rates, and so on 3 A summary of the walkthrough audit findings and results 4 Model the existing building using a detailed energy simulation tool 4 Basic assumptions made to model the building using a detailed simulation tool 5 Perform engineering calculations to estimate energy savings from potential energy conservation measures 5 Description of the calibration process 6 Perform an economic analysis for all the energy conservation measures 6 A summary of the economic analysis 7 Select the energy conservation measures to be recommended for implementation 7 A list of the implementation priority based on the economic analysis standard energy audit also includes tasks from walkthrough audit Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Practical advices – reporting for Standard Audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Thermal zone Introduction The building or the building complex is divided into thermal zones - independent parts of the building, characterised by the different usage made, HVAC or electrical facilities, with different criteria of usage or independent indoor environmental control systems and management Building refurbishment Geometric characteristics and facility equipment of the building complex Assessment & evaluation Thermal Zone No. Gross Volume (m3) Description Net Floor Area (m2) Facility equipment Material science Modern technology Renewable energy Cost control Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Practical advices – reporting for Standard Audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings Checklist of technical documents for building features Building refurbishment Documents Material science Teritorial framework Description Checklist of technical documents for building facilities features Documents Plan with teritorial framework of the building enables to define the guidelines and the context surrounding area (shadow, vegetation, etc) Design drawings Project on plan HVAC System Other Functional diagrams Elevations (scale) Characteristics of opaque envelope Electrical systems Project on plan Technical support Safety report Characteristics of transparent envelope Other facilities Other (specify) Cost control Technical support Safety report Sections (scale…) Building envelope Description Functional diagrams Plans (scale…) Modern technology Renewable energy LU3 Technical and operating documentation Introduction Assessment & evaluation LU2 Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 Practical advices – reporting for Standard Audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings Introduction LU2 LU3 Green energy audit goals 1. to contribute to an overall improvement in the sustainability of the building. 2. conservation of energy becomes conservation of resources. 3. the auditor has two objectives: to maximise energy performance and to maximise environmental quality; 4. measures that use renewable energy are preferred; 5. the auditor considers all natural solutions in the building, such as green roofs, green facades, natural shading systems, passive solar and daylighting systems; 6. evaluation of sustainability targets (LEED, BREEAMS, others) Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Applied from: Jayamaha L. Energy efficient building systems. New York NY: McGraw Hill; 2006 From energy audit to green audit 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings LU2 LU3 Introduction Energy auditor experience Building refurbishment Assessment & evaluation Material science Modern technology • green/sustainable design of buildings; • design of energy systems (mechanical and electrical); • energy management; • energy accounting; • international environmental protocols (LEED, BREEAMS or others) Renewable energy Cost control Energy auditor skills • the ability to operate in the field; • a knowledge of current security issues; • competence in using survey and monitoring instruments; • the ability to communicate and interact not only with the client but also with his staff; • the ability to write the audit reports clearly and effectively; • ensured continuing professional development (CPD), covering all updates in norms and regulations so that there can also be; • the availability to allow for and handle continuous updating of the technical and legislative requirements • confidentiality in handling information Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 From energy audit to green audit – energy auditor 12 13 Back Next Module 2: Assessment & evaluation LU1 Learning Unit 3: Energy audit in buildings Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Owner/client Owner/client Facility manager Maintenance manager Contract definition Acquisition of docs Facility management Activities plan Definiton of consumption indicators Owner/client Facility manager Maintenance manager Building facilities Field survey Benchmark Environmental condition Measures Monitoring Baseline definition Owner/client Owner/client Choice of retrofit measures Sustainability evaluation of the measures Audit report Technical evaluation Economic evaluation LEED Protocol LU3 Flow diagram of a green energy audit process Introduction LU2 Green Energy Plan Applied from: Dall’O G. Green energy audit of buildings. London UK: Springer-Verlag; 2013 From energy audit to green audit – energy auditor 12 13 Back Next Module 3: Material science Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Learning objectives. To give: 1. basic knowledge on energy efficiency and thermal comfort in buildings; 2. knowledge on various categories of building materials, their characteristics and use; 3. knowledge on modern technologies used in energy efficient buildings. Cost control Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics LU2 LU3 Heat exists in sensitive form, which means temperature-related, or in latent form, which means as transformation heat Introduction Sensitive heat is transferred by: Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Conduction Convection Radiation heat is transferred between solids at different temperature in contact with each other and between points at different temperature within the same solid occurs in a pronounced way close to the contact between liquids and gases at one side and solids at the other. We distinguish forced, natural and mixed convection radiation refers to heat transfer, caused by the emission and absorption of electromagnetic waves. Heat transfer through radiation does not need a medium Latent heat moves along with a carrier, independent of temperature. Each time the carrier undergoes a change of state, related latent heat is converted into sensitive heat or vice versa Example: when water evaporates, it absorbs sensitive heat in a quantity equal to its latent heat of evaporation Applied from: Hens H. Building physics – heat, air and moisture. Berlin GE: Ernst & Sohn Verlag; 2007 Heat & mass transport - definition 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics LU2 LU3 Introduction Building refurbishment Mass transferThe term ‘mass transfer’ points to the transfer of air, water vapour, water, dissolved solids, gases and liquids in and through materials and building constructions. Assessment & evaluation Material science As examples, we have the airfow in a room, the transport of water vapour through a roof, the movement of water and salts in bricks, the diffusion of blowing agents out of insulation materials Modern technology Renewable energy Cost control Air and moisture are of the utmost importance for the physical integrity of buildings. When the open pores in a material are not filled with water, they contain humid air. Water can enter a pore only when the humid air is pushed out Moisture is the most destructive for buildings. A correct moisture tolerance is a challenge for each designer and builder. The word ‘moisture’ indicates that water in porous materials is present in its two or three phases, with different substances dissolved in the liquid phase Applied from: Hens H. Building physics – heat, air and moisture. Berlin GE: Ernst & Sohn Verlag; 2007 Heat & mass transport - definition 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics LU2 LU3 Introduction people A c t i v e Building refurbishment Assessment & evaluation lighting solar gain h e a t i n g Material science A c t i v e equipment c o o l i n g conduction ventilation Modern technology Moving target Fabric storage Renewable energy Different levels of refurbishment offer greater or lesser opportunities to affect all the elements of the balance to set the building up for the next phase of its life, from improving the efficiency of mechanical systems to altering the size and distribution of heat loads from people, equipment and lighting, and even to altering characteristics of the building envelope through changes to the facade or exposing previously inaccessible thermal mass Balance of heat inputs and losses from a building in a cool climate Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Heat & mass transport 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics Introduction Hygroscopicity and capillarity measure the capacity of a material to absorb and desorb water as a gas (water vapour) and liquid respectively, from and to the air, or condensation, as the relative humidity of the air changes Building refurbishment Assessment & evaluation Material science LU2 LU3 The speed with which a wall surface can absorb moisture is important for avoiding surface condensation. Materials with a combination of vapour permeability and high absorption can quickly moderate humidity variations by storing or releasing significant quantities of water The hygroscopic capacity of a material is related to its equilibrium moisture content and is sometimes measured as the percentage increase in water content in a material when the relative humidity increases from 50% to 85% with a constant temperature of 21°C Modern technology Renewable energy Cost control Applied from: Hens H. Building physics – heat, air and moisture. Berlin GE: Ernst & Sohn Verlag; 2007 Hygrothermal behavior in buildings – hygroscopic capillary properties 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics Introduction LU2 LU3 Air pressure difference Building refurbishment Solar radiation (direct and diffuse) Interior Heat exchange with outdoor environment Exterior Assessment & evaluation Heat exchange with indoor environment Wind driven rain Material science Vapour exchange with indoor air Vapour exchange with outdoor air Modern technology Renewable energy The main function of a building envelope is the protection of an enclosed space from the natural exterior environment Groundwater Hygrothermal loads and their alternating diurnal or seasonal directions acting on the building envelope according to ASHRAE Cost control Applied from: Hens H. Building physics – heat, air and moisture. Berlin GE: Ernst & Sohn Verlag; 2007 Hygrothermal behavior in buildings – hygrothermal loads 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics LU2 LU3 Types of ventilation systems Introduction Mechanical ventilation Building refurbishment Ventilation is provided by a network of ducts, powered by a fan or fans Natural ventilation Basic types of mechanical system: Assessment & evaluation ventilation arises from flows through openings in the envelope, which are generated by the natural forces due to wind and buoyancy (gravity). Material science Modern technology Renewable energy Cost control Extract only the air is extracted through ducts, with openings in the envelope providing the route for air supply Supply only Supply & extract air is supplied through the ducts, and openings in the envelope provide the exhaust route separate duct networks perform the supply and extract functions, which, if the mass flow rates are equal, is referred to as a balanced system Applied from: Hall MR. Materials for energy efficiency and thermal comfort in buildings. Cambridge UK: Woodhead Publishing Ltd; 2010 Ventilation & air quality – ventilation systems 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics LU2 LU3 Introduction Building refurbishment can improve energy efficiency by conserving energy, that otherwise would have been wasted, for later use. Additionally the fluctuations of temperature that compromise the efficiency of thermal systems may also be minimised Assessment & evaluation Material science Modern technology The role of thermal energy storage can maximise the output from an intermittent renewable energy supply source, such as solar radiation, by increasing its accessibility to applications such as building cooling and heating Renewable energy Cost control Applied from: Hall MR. Materials for energy efficiency and thermal comfort in buildings. Cambridge UK: Woodhead Publishing Ltd; 2010 Heat energy storage & cooling 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics Introduction The materials used as storage media are in either solid or liquid phases. Solid materials possess thermal density values far higher than liquid media. The thermal density of concrete is approximately 466 times greater than that of water at 20 ºC Building refurbishment Assessment & evaluation The term ‘phase change material’ (PCM) refers to materials that store thermal energy in the phase change from solid to liquid. PCMs can broadly be arranged into two categories: salt hydrates and organic materials Material science Chemical thermal storage materials work as pairs in thermal storage systems. The sorbent is a component of the working pair in a sorption type chemical thermal storage system. The sorbent is not responsible for storing the thermal energy, and thus, its thermal mass is not of major concern Modern technology Renewable energy Cost control LU2 LU3 Materials for sensible heat storage The large size, non-metallic solid blocks are not suitable for applications that require high rate heat storage with a frequent charge/discharge cycle. Metallic solid materials perform much better in this respect, though the high cost of the metals makes it uneconomic Materials for latent heat storage PCM The encapsulated small PCM particles reduce the heat travel distance within the PCM and provide a larger specific surface to volume ratio; this is an effective way to improve the overall heat transfer of the latent heat storage systems Materials for chemical heat storage Chemical thermal storage is very suitable for incorporating with certain heat powered refrigeration systems, such as vapour absorption and adsorption, to provide cooling to buildings. The working pairs used in these systems can be used directly as thermal storage materials Applied from: Hall MR. Materials for energy efficiency and thermal comfort in buildings. Cambridge UK: Woodhead Publishing Ltd; 2010 Heat energy storage & cooling - materials 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 1: Basics of building physics LU2 LU3 Introduction Type ISO Description Type I 3rd party environmental labelling BS EN ISO 14024:2001 Label: 3rd party standard that awards a licence which authorises the use of labels on product within particular category based on life-cycle consideration. Commonly reffered to as ECOLABELS Type II Self declared environmental claims BS EN ISO 14021:2001 Claim: self-declared claim as statement or symbol indicating environmental aspect of a product (product is recyclable, for instance) Type III 3rd party verified environmental declaration (EPD) BS EN ISO 14025:2006 Declaration: a set of quantified environmental data consisting of preset parameters based on LCA according to ISO 14040. Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Environmental labelling and declaration according to BS EN ISO 14020 Cost control Environmental profiling of building materials 1 2 3 4 5 6 7 8 9 10 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency LU2 LU3 Introduction Building refurbishment Thermal conductivity (k) Thermal conductivity, k (also known as psi), tells us how well a material conducts heat R-value The R-value is a measure of how well a material resists heat travelling through it. It is the ratio of the temperature difference across an insulator and the heat flow per unit area through it. The bigger the number the better the insulator U-value R-value is the reciprocal of U-value (and vice versa). A lower U-value is better indicating greater insulation value. It is commonly used in Europe describing the rate of heat transfer through a building element over a given area, under standardized conditions Easy of installation Sheets and batts are perfect for large areas, where the distances between joists are standard sizes or where shapes are rectangular. Loose-fill cellulose can easily be blown into a horizontal space and unusual shapes Assessment & evaluation Material science Modern technology Thermal insulation of buildings is one of the most effective ways to save energy resources for heating and cooling Cost Renewable energy Cost control Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 High performance insulation materials – description of insulation 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency Introduction Building refurbishment Assessment & evaluation Material science Wood fibre batts Cotton-based batts and rolls K-value: 0.038–0.043W/mK (CIBSE, 2006). A recyclable, renewable resource with a low embodied energy Safe to install. Can absorb some moisture whilst remaining efficient, but when very wet assumes the U-value of water – high. Naturally resistant to decay and fungus. Expensive K-value: 0.038–0.043W/mK. Hygroscopic up to 20 per cent. Easy and safe to install, no irritating fibres. Good dimensional stability. Recyclable, renewable, biodegradable, non-hazardous. Good for most structural elements. Embodied energy: 20MJ/kg or 2800MJ/m3 at 140kg/m3 K-value: 0.038–0.043W/mK. Recyclable, a natural, nonhazardous fibre that’s safe to install. Cotton mill scraps or recycled cotton is mixed with a bulking fibre such as hemp and a thermoplastic binder like polyester Cellulose (loose, batt or board) Flax batts, slabs and rolls Hemp batts Renewable energy Cost control LU3 Sheep’s wool batts and rolls K-value: 0.038–0.040W/mK. Recyclable, renewable, made from finely shredded newspaper, safe to install. Loose-fill is blown in dry, e.g. in lofts, or wet on nonhorizontal spaces Modern technology LU2 K-value: approximately 0.042W/mK. Made from a plant whose fibres are bound together with potato starch and treated with borax to make them fire and insect resistant. Recyclable, renewable, a natural, nonhazardous fibre, safe to install K-value: 0.043W/mK. Recyclable, renewable, natural, nonhazardous. Like wool and cotton batts, contains 15 per cent polyester fibre to retain lift and stability and borax. Biodegradable. Relatively expensive Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 Organic materials High performance insulation materials – thermal properties of materials 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency Introduction Building refurbishment Assessment & evaluation LU3 Coconut fibre board Cork board Wood fibre board K-value: 0.045W/mK. Made from the outer husk of coconuts with borax and minimal processing. Made into batts or used in screed or timber floor and ceiling constructions. Sustainable/ renewable, with variable embodied energy; recyclable biodegradable K-value: 0.042–0.050W/mK. Renewable resource from largely sustainably managed cork forests (harvesting the outer bark of cork oak), may contain recycled cork. Commonly used as underlay under hardwood and ceramic floors K-value: 0.080W/mK. The rigid insulation has a higher (worse) Uvalue than the batt form. Works due to sealed air cells within the fabric. Fire-resistant and uses no glue (formed under high pressure). Recyclable, renewable, biodegradable in landfill, nonhazardous Strawboard Hemcrete K-value: 0.101W/mK. Recycled, recyclable, renewable agricultural waste – 100 per cent straw. Produces its own binding resin. Biodegradable K-value: 0.12–0.13W/mK. Comprises hemp shiv with a lime matrix. High elasticity and vapour permeability. Long-lasting, flexible, low embodied energy. Easy to install Material science Modern technology LU2 Renewable energy Cost control Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 Organic materials High performance insulation materials – thermal properties of materials 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control LU2 LU3 Mineral wool batts and rolls Foamed glass slab Perlite K-value: 0.033–0.040W/mK. Made of steel slag (over 75 %) with basalt rock (25 % or less). Used for loft and cavity wall insulation – blown in through a hose. Fireproof, recyclable, long-lasting, rotresistant. Non-renewable, non-biodegradable, highly reliant on fossil fuels K-value: 0.042W/mK. Contains tiny sealed cells formed by reacting finely-ground oxidized glass (up to 60 % recycled) with carbon at high temperature. High, durable compressive strength, nonpermeable, high thermal mass, inherently resistant to fire and air movement. Re-usable K-value: 0.045–0.05W/mK. Naturally occurring volcanic glass that greatly expands and becomes porous when heated sufficiently. Loose-fill, granular, light weight. To fill concrete block cores, or mixed with cement to create a lighter, less heat-conductive concrete. Non-renewable, mined Fibreglass mineral wool batts and rolls Aerogel K-value: 0.033–0.040W/mK. Made from molten glass, sometimes with 20 to 30 % recycled content. The most common residential insulant. Usually applied as batts, pressed between studs. Non-renewable, durable and rot-proof, non-flammable, except for the facing, nonbiodegradable, reclaimable, not recyclable. Risks of cancer and breathing problems from exposure to glass fibres K-value: 0.013W/mK. Aerogel has given rise to highly expensive new products such as flexible sheets and laminates, a type of glass and composite materials including plasterboard and sandwiched within PVC panels. Uneconomic but useful where width is limited as performance is so good. Made by extracting water from silica gel, replacing it in nano-sized pores with a gas such as carbon dioxide to comprise 99 per cent of volume. Stable and rigid, durable and rot-proof, impermeable to water-vapour, non-combustible, reclaimable. non-renewable and non-bio-degradable Natural minerals Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 High performance insulation materials – thermal properties of materials 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control LU2 LU3 Phenolic foam board Expanded polystyrene board Extruded polystyrene board K-value: 0.020–0.25W/mK. Closed cell phenolic foam is designed for roofing, cavity board, external wall board, plaster board dry linings systems, floor insulation and as sarking board (EPS) K-value: 0.032–0.040W/mK . Thermoplastic, melts if heated (for moulding or extrusion). Expanded into foam using heat. They are used primarily in masonry cavities. Can be recovered for re-use. Boards not recommended for older, breathable constructions (XPS) K-value: 0.028–0.036W/mK. Uniform closed-cell structure, smooth continuous skin. Some products use recycled polystyrene. Very high compressive strength Eco-wool – batts Structural Insulated Panels K-value: 0.039–0.042W/mK. Recycled alternative to glass wool. Comes in rolls or slabs of varying thicknesses. Suitable for loft and stud walls. Easy to install, reclaimable/recyclable, stable, durable, non-toxic. impermeable to watervapour. non-biodegradable K-value: variable approximately 0.040W/mK. A building method using pre-cut EPS or XPS to erect an airtight structure quickly that eliminates thermal bridging. For renovation work they may be used for building extensions or new walls or even external insulation. Many different applications Polyurethane board and foam K-value: 0.02–0.033W/mK. Foam or rigid board. Foam is sprayed in at high temperatures. Stable, durable, ideal for plugging gaps or leaks. Any thickness can be achieved. Hydrophobic Fossil carbon Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 High performance insulation materials – thermal properties of materials 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency LU2 LU3 Introduction PCMs can be organic, paraffin or nonparaffin based, inorganic like salt hydrate or metallics, or inorganic eutectics when PCMs are composed of two or more components which freeze and melt in a congruent manner Building refurbishment Assessment & evaluation Material science PCMs can store a significant amount of thermal energy at daytime while melting, thus reducing the indoor air temperature swings produced by solar and internal gains Modern technology At night, thermal energy is released and the material can restore its solid state; this stage can be enhanced by ventilating the building with fresh outdoor air Renewable energy Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Phase change materials - PCM 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency Introduction Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control LU2 Passive PCM systems Active PCM systems Passive use of PCM - to decrease the operation energy of the building by decreasing the energy demand of space heating and cooling, basically smoothing the indoor temperature by increasing the energy inertia of the building envelope Active systems using PCM - to decrease the operational energy of the building by decreasing the use of fossil fuels in heating, cooling and domestic hot-water production PCM wallboards is used to improve the thermal comfort of lightweight buildings, since they are very suitable for the incorporation of PCM In solar water heating systems, the use of PCM can be an advantage since the volume of the necessary water storage tank can be decreased LU3 Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Phase change materials – building refurbishment 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 2: Materials for improving energy efficiency Characteristics Introduction Assessment & evaluation Material science Modern technology Renewable energy Cost control LU3 Syntetic materials Energy used in manufacture Low, in solid materials energy is used in processing Usually high Added chemicals Glues with low impact are added Some products contain toxic glues or other chamical agents (e.g. formaldehyde) Robustness Some insulations are highly robust Some products are very robust Ability to handle moisture Some insulations are able to handle moisture very well Most insulations are unable to absorb moisture Moisture buffering Many insulations can help to regulate humidity Most materials do not regulate humidity Breathability Most materials are breathable and moisture permeable Most materials are not breathable Indoor air quality (IAQ) Most insulations help with good IAQ Neutral or negative on IAQ Recycling Some include recycled and waste materials Some materials are based on recycled resourses End-of-life disposal & pollution Natural materials can decay back into the earth Can be classified as hazardous waste Ozone depletion No or low negative effect Many products use chemical blowing agents Thermal mass Most materials contain varying levels of thermal mass improving thermal performance Most materials do not contribute to thermal mass Durability Most materials are durable Many materials are not durable Renewable vs. non-renewable materials Building refurbishment Natural renewables LU2 Applied from: Woolley T. Low impact building. Housing using renewable materials. Oxford UK: John Wiley & Sons; 2013 Materials for energy efficiency in buildings 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science Learning Unit 2: Materials for improving energy efficiency LU1 LU2 LU3 Introduction Criteria for selection of materials Building refurbishment How does the material affect health and the ecosystem, and how does it affect resource use Assessment & evaluation How does the environmental damage? Regarding health, it is the emissions and chemical ingredients that are decisive. Regarding resource use, environmental profiles produced using lifecycle analysis can be examined Material science Modern technology Renewable energy Cost control Applied from: Bokalders V, Block M. The whole building handbook. How to design healthy, efficient and sustainable buildings. London UK: Earthscan; 2010 Materials skills for building refurbishment 1 2 3 4 5 6 7 8 9 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices Introduction LU2 LU3 The refurbishment of the opaque elements of existing buildings means using thermal insulation materials Building refurbishment Main solutions for thermal insulation Assessment & evaluation Material science Refurbishment levels, to enhance the energy saving external insulation Level 1 existing level/insulation condition internal insulation Level 2 standard refurbishment measures air layer insulation Level 3 advanced refurbishment measures Modern technology Renewable energy Cost control Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Opaque building envelope 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices LU2 LU3 Main Parameters for the Thermal Characterization of Walls Introduction Evaluation of U [W/(m2 K)] Building refurbishment Assessment & evaluation Calculation EN ISO 6946:2008 Material science In situ measurement Definition of wall layers Modern technology Project information Heat flux meter analysis (ISO 9869) Comparison with wall catalogue Endoscopy Renewable energy Wall U-value definition Cost control Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Opaque building envelope – thermal transmittance 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices Introduction LU3 Vapour transmission problems Building refurbishment The moisture problems affect building structures are various: Assessment & evaluation Side effects resulting from interstitial condensation produce degradation of buildings and unhealthy environments in the following forms: capillary rise of water in the walls condensation inside building components migration of salts, efflorescence problems with tightness to rainwater dimensional changes and damage of artefacts salts migration inside materials Material science reduction in the thermal insulation hygrometric surface problems degradation of plaster water vapour condensation inside structures decay of wooden structures Modern technology the presence of condensed water on the surface and inside of the walls growth of fungal colonies on the inner surface of the building envelope Renewable energy Cost control LU2 Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Opaque building envelope – vapour transmission problems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices LU2 LU3 Thermal transmittance conditions and improvement actions Introduction Building refurbishment Radiation Low-e coatings Conduction Assessment & evaluation Special gas fills Multiple cavities Convection Material science Modern technology Renewable energy Cost control Low conductance spacers Better frames Conduction Windows are the most energytransmissive elements in the envelope with U-value at least five times greater than typical insulated opaque elements Windows transmit around 400W/m2, 40 times greater than a 20°C temperature difference across a wall with a Uvalue of 0.5W/m2 Thermal transmittance of a window (UW) is defined by 3 components: the glass panes, the frame (fixed or operable), and the spacer between panes (multiglazed windows) Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Transparent building envelope – thermal transmittance 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices LU2 LU3 Introduction Building refurbishment the introduction of coating film over the glass panes with a consequent emissivity reduction (lowemission glazing) Assessment & evaluation Material science the application of gas layer with a thermal conductivity lower than the air conductivity (for instance, argon and krypton gases) Solutions used for the reduction in conductive and convective heat transfer the addition of interspaces splitting with multiglazing systems Modern technology the adoption of spacers with low thermal conductivity material components Renewable energy Cost control Applied from: Baker NV. The handbook of sustainable refurbishment. Non-domestic buildings. London UK: Earthscan; 2009 Transparent building envelope – solutions 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices Introduction LU2 LU3 The effectiveness of sun protection of glass surfaces depends on the following factors: Building refurbishment Assessment & evaluation characteristics of the screen materials and finishing (reflectance) solar shading solution (fixed or mobile) screen positioning with respect to the frame (external, internal, intermediate) screen disposition, according to the façade exposition (parallel, orthogonal, horizontal, vertical, etc.) Material science Modern technology Renewable energy Cost control Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Shading devices 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices Introduction Fixed shading examples LU2 LU3 Mobile shading examples Building refurbishment Roller blinds Assessment & evaluation Fixed overhang Material science Modern technology Venetian blinds Renewable energy Cost control Fixed blades Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Shading devices – classification of shielding products 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices Introduction Roller blinds examples LU2 LU3 Curtains examples Building refurbishment Assessment & evaluation Roller curtain Drop-arm awning Material science Modern technology Renewable energy Cost control Sliding arm awning Tent canopy Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Shading devices – classification of shielding products 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices LU2 LU3 How to Choose a Solar Shading Device Introduction Building refurbishment solar gain reduction in summer summer thermal comfort improvement by controlling the phenomena of radiative heat exchange Assessment & evaluation Functional benefits that should be evaluated Material science visual comfort by controlling glare effects Modern technology Renewable energy Cost control thermal resistance improvement in the combination frame/screen thermal winter solar gains In case of historic buildings it is crucial to evaluate the aesthetic value of facades before choosing appropriate shading device (external, internal, intermediate) Applied from: Magrini A. Building refurbishment for energy performance. A global approach. Dordrecht CH: Springer International Publishing; 2014 Shading devices – classification of shielding products 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices Introduction LU3 Silica aerogels is a highly porous nanostructured and light material, with a very low thermal conductivity (down to 0.010 W/m K). Granular translucent and transparent monolithic silica aerogels were developed as insulation materials for windows Building refurbishment Types of aerogels Assessment & evaluation Material science Modern technology 1 2 opaque aerogels, could be used to reduce thermal bridges in the building envelope, or additives for high thermal performance coatings. The thermal conductivity is about 0.013 W/m K transparent aerogels, such as monolithic aerogels for superinsulating windows Renewable energy Cost control LU2 3 Buildings dated before 1970 usually do not have very large windows, but their performance in terms of thermal insulation is generally very poor translucent granular silica aerogels (often called nanogel), used to realize highly energy-efficient windows and skylights. Uvalues can be lower than 0.3 W/m2 K Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Windows: nanogel & energy efficient 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 3: Material science LU1 Learning Unit 3: Systems & devices LU3 Commercially available glazing systems Introduction 2 1 tensile structures and roofing Building refurbishment Assessment & evaluation polycarbonate systems for skylights and façades 3 insulated glass units Material science Modern technology 4 5 structural composite panels for skylights and façades U-channel glass (self-supporting systems of glass channels with an extruded metal perimeter frame) Renewable energy Cost control LU2 Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Windows: nanogel & energy efficient 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4:Modern technology Introduction Building refurbishment Assessment & evaluation Material science Modern technology Learning objectives. To give: 1. basic knowledge on modern technologies used in energy efficient buildings; 2. knowledge on thermal energy storage technologies; 3. information about low energy cooling systems; 4. knowledge on HVAC systems in energy efficient buildings; 5. information about Energy efficient lighting; 6. knowledge on Switchable glazing technology. Renewable energy Cost control Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Thermal energy can be stored as part of the building structures as well as in a separate enclosure, which purely depends on the method of cooling/heating being provided in the existing building envelope Building refurbishment Assessment & evaluation Material science Passive Thermal Storage using some part of the building mass (block walls, block partitions, concrete floors, and concrete roof decks) to store heating or to store cooling capacity Active Thermal Storage takes place when a material is specifically cooled or heated, with the object of using the cooling or heating effect at a later time Modern technology Renewable energy Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Thermal energy storage (TES) technologies 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Building refurbishment Assessment & evaluation Passive Solar Heating Storage Active Solar Heating Storage The passive heating using the solar energy is a type of thermal storage technique highly suitable for buildings that are being refurbished The active solar heating storage utilizes a dedicated solar collector, storage tank, heat exchanger, associated mechanical pumps and control interfaces.The solar radiation being trapped by the solar collector gets converted to heat energy Passive solar heating storage systems can enhance energy efficiency of buildings by 30–35 % The temperature of heat transfer fluid is expected to elevate up by 130–140◦C Material science Modern technology Renewable energy Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Thermal energy storage (TES) technologies – Solar heating storage 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Summer Building refurbishment Assessment & evaluation The aquifer thermal energy storage (ATES) system basically works on the principle of extracting the enthalpy of thermal energy from the lowtemperature groundwater to cater the cooling or heating load demand in buildings. Room heat exchanger Material science Heat exchanger Modern technology 50-200 Renewable energy Aquifer Earth Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Thermal energy storage (TES) technologies – Aquifer thermal energy storage (ATES) 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Winter Building refurbishment Three types of ATES systems capable of storing heat or cold depending on the thermal load demand in buildings Assessment & evaluation Room heat exchanger Material science 1. single (mono)-source, 2. double-source (doublet) 3. recirculation (year-round) Heat exchanger Modern technology 50-200 Renewable energy Aquifer Earth Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Thermal energy storage (TES) technologies – Aquifer thermal energy storage (ATES) 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Summer Building refurbishment Assessment & evaluation The borehole thermal energy storage (BTES) systems are similar to the ATES systems in operational characteristics Room heat exchanger Material science Heat exchanger Modern technology Renewable energy Cost control Earth Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Thermal energy storage (TES) technologies – Borehole thermal energy storage (BTES) 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Winter Building refurbishment Assessment & evaluation The BTES system utilizes the low-temperature source from the underground for effectively catering the cooling and heating requirements in buildings Room heat exchanger Material science Heat exchanger Modern technology Renewable energy Cost control Earth Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Thermal energy storage (TES) technologies – Borehole thermal energy storage (BTES) 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Radiant cooling systems utilize chilled water pipes to distribute cooling energy to various conditioned spaces Building refurbishment Type of radiant cooling systems Assessment & evaluation Material science Modern technology Renewable energy Cost control Panel system Capillary tube system Aluminum panels that carry tubing can be surface mounted or embedded on floors, walls, or ceilings. Thermal mass of a heated floor acting as heat storage medium. Heat is conducted from the heating sources to the panel surfaces. By radiation, the surfaces directly heat objects without heattransferring media (such as air) Capillary tube systems are used to provide chilled water through mats of small, closely spaced tubes that are embedded in plastic, gypsum, or plaster on walls and ceilings. Concrete layers with embedded tubes can provide the conduit and thermal storage capacity for cooling systems Applied from: Krarti M. Weatherization and energy efficiency improvement for existing homes. An engineering approach. Boca Raton FL: CRC Press; 2012 Low energy cooling systems – Radiant cooling systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices The ASHRAE design recommendations Introduction Building refurbishment ASHRAE recommendation 1 Room temperature 18 - 22⁰C 2 Supplied hot water temperature 35 - 60⁰C 3 Floor surface temperature 24 - 30⁰C Material science 4 Drop in water temperature 8 - 11⁰C 5 Maximum length of loop 60m (3/8 in.), 90m (1/2 in.) Modern technology 6 Tube size 3/8 in. 7 Tube spacing 10 – 23 cm Assessment & evaluation Renewable energy Cost control Applied from: Krarti M. Weatherization and energy efficiency improvement for existing homes. An engineering approach. Boca Raton FL: CRC Press; 2012 Low energy cooling systems – Radiant cooling systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Classification of Heating and Cooling Systems Introduction Function Building refurbishment Heating only Cooling only Heating & cooling Forced air systems Furnaced with ducted air orductfree air DX air conditioning; evaporative cooling Air heat pumps Hydronic systems Boilers and baseboard radiators; radiant floors Radiant celling Radiant walls Modern technology Passive/renewable systems Direct gain systems; trombe walls Earth air tunnels; natural ventilation Ground source heat pumps Renewable energy Others Electric heaters; wood stoves Absorption cooling Thermoactive foundations Assessment & evaluation Material science Heating, Ventilating, and Air Conditioning (HVAC) Cost control Applied from: Haines RW, Myers ME. HVAC systems design handbook. New York NY: McGraw Hill; 2004 HVAC systems in energy efficient buildings 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Criteria for System and Equipment Selection Building refurbishment Criteria for HVAC System and equipment selection 1 Demands of comfort or process Assessment & evaluation 2 Energy conservation, code requirements 3 First costs vs. Life-cycle cost Material science 4 Desires of owner, architect or design office 5 Space limitation Modern technology 6 Maintainability and reliability Renewable energy 8 Simplicity and controllability Cost control 7 Central system or distributed system Applied from: Haines RW, Myers ME. HVAC systems design handbook. New York NY: McGraw Hill; 2004 HVAC systems in energy efficient buildings 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction 1 Building refurbishment 3 The building has no heating or cooling system. Energy is used only for systems such as lighting, appliances, and DHW. This case was considered as a reference to assess the level of thermal discomfort within the building if no heating and cooling systems are installed Assessment & evaluation Material science 2 Renewable energy Radiative walls Radiative walls are used to heat and cool the apartment unit. Three thermostats per unit are used to avoid significant temperature stratification. To operate the system, operative temperature control is used Natural ventilation 4 The building is cooled using natural ventilation. No mechanical system is used for heating or cooling. Natural ventilation is considered by opening windows only when outside air temperature is lower than 23°C and indoor and outdoor temperature difference is 1°C over the indoor temperature Modern technology Cost control No HVAC system Earth tube This option utilizes the heating/cooling energy stored within the ground medium. In this building, an earth tube is used to condition air supplied to each apartment unit in the building Applied from: Krarti M. Weatherization and energy efficiency improvement for existing homes. An engineering approach. Boca Raton FL: CRC Press; 2012 Comparative analysis of heating & cooling systems – types of HVAC systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction 5 Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control Radiative wall with cooling tower This system is a variation of system 4 with an open type cooling tower (condenser) loop directly connected to the radiative wall system loop to reduce cooling energy consumption 6 Radiative wall with evaporative cooler This system is also a variation of system 4 with an evaporative cooler used to cool the water supplied to the radiant walls 7 Radiative floors Instead of the radiative walls, radiative floors are utilized to provide both heating and cooling throughout each apartment unit of the building. A radiative floor per floor level for each unit is considered 8 Heating with radiative floor and cooling with radiative wall This system used two separate water loops: hot water loop to provide heating through the radiative floors as in system 8, and chilled water loop to provide cooling through radiative walls as in system 3 Applied from: Krarti M. Weatherization and energy efficiency improvement for existing homes. An engineering approach. Boca Raton FL: CRC Press; 2012 Comparative analysis of heating & cooling systems – types of HVAC systems 12 13 Back Next Module 4: Modern technology Learning Unit : Modern technology systems & devices Introduction Building refurbishment Energy-Efficient Lighting Systems Lighting controls High-efficiency fluorescent lamps Assessment & evaluation Material science Modern technology Compact fluorescent lamps Compact halogen lamps LED lighting Organic Light-Emitting Diodes Automatically turning off the lights in spaces that are not occupied and can detect motion for spaces of up to 60 m2 , can save up to 60% of energy use Occupancy or Vacancy Sensors Photosensor-Based Controls Timers and motion detection can save 20% of energy use associated with outdoor lighting Renewable energy Cost control Dimming Switches can save up to 50% of the electrical lighting energy use Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 Energy efficient lighting 12 13 Back Next Module 5: Renewable energy systems Introduction Building refurbishment Assessment & evaluation Material science Learning objectives. To give: Modern technology Renewable energy 1. knowledge on small scale renewable energy systems and devices used in buildings; 2. knowledge and information about solar photovoltaic devices and systems, solar thermal devices and systems, wind energy for homes, heating pumps, micro CHP power generation, design principles for RES installations. Cost control Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Building refurbishment Renewable energy technology Assessment & evaluation Solar thermal (tube) Upgrading domestic hot water system Installation may be integrated with roof refurbishment-close to cost effective Solar thermal (flat plate) Low temperature applications Even unglazed flat-plate collector can be effective for low temperature spplication Material science Photovoltaic Re-cladding panels and roof tiles Photovoltaic/thermal Re-cladding with air-cooled PV panels Electricity generation and ventilation pre-heating. Cooled panels work at higher efficiency Modern technology Photovoltaic Opaque PV used as shading devices Geometry for optimum collection and shading tends to coincide Photovoltaic Semi-transparent PV used for reduced transmission glazing panels in large spaces (atria) Not optimum shading since PV is about 85% absorber and re-radiates absorbed energy inwards Renewable energy Cost control Application Comments Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Renewable energy options 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Building refurbishment Renewable energy technology Application Comments Biomass heating System requires space for fuel delivery and storage; waste materials storage/disposal (ashes) Local emission regulations need consulting Ground source heating Uses a heat pump Operates at low temperaturerequiring an appropriate delivery sysytem, underfloor heating Material science Ground source cooling Uses a heat pump Increasing efficiency of refrigeration due to lower temperature cold sink. Displaces electricity. Often used in conjunction with heating Modern technology Solar thermal (cladding collector) Re-cladding in conjuction with external insulation Heated air collected between lightweight absorber and external insulation Solar thermal (tube) Contributing to space heating in buildings with low heat demand and integrated storage system Installation may be integrated with roof refurbishment Assessment & evaluation Renewable energy Cost control Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Renewable energy options 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Building refurbishment Suitability of renewable energy sources Assessment & evaluation Application Solar thermal Solid biomass Biomass from waste Biogas Shallow geothermal Deep geothermal Dwellings Material science District heating Commerce & service Modern technology Agriculture Renewable energy Cost control Industry Applied from: Ziębik A, Hoinka K. Energy systems of complex buildings. London UK: Springer-Verlag; 2013 Renewable energy options 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Typical grid connected PV system for a house Building refurbishment Assessment & evaluation Most PV systems installed for residential buildings are used to generate electricity that can be either used directly in the house (stand-alone systems) or sold to the grid (grid-connected systems) Inverter PV panel Sockets Material science Panel board Room Modern technology Utility power Renewable energy Cost control Recently, there is an interest in using hybrid PV systems to generate both electricity and heat through photovoltaic/thermal (PV/T) collectors Bathroom Meter Applied from: Krarti M. Weatherization and energy efficiency improvement for existing homes. An engineering approach. Boca Raton FL: CRC Press; 2012 Solar photovoltaic devices & systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Fully filled solar thermal system Building refurbishment Roof Assessment & evaluation Solar collector Material science Hot water store Modern technology Expansion vessel Pump Renewable energy Cost control The flat type, which is the most common and the most economic, is formed by a radiation collection plate, by one or more glass coverings, in order to reduce thermal loss externally, as well as a system of channels connected to the plate through which a thermo-vector fluid flows to remove power Check valve Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 Solar thermal devices & systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Drainback solar thermal system Building refurbishment The energy performance of a system is influenced chiefly by: Roof Assessment & evaluation - Drainback vessel Material science - Solar collector - Hot water store Modern technology Pump the amount of solar radiation hitting the collectors; the collector type (panels or evacuated tubes); their efficiency; the orientation (azimuth); the slope; the end-use water temperature and volume required Renewable energy Cost control Applied from: Thorpe D. Sustainable home refurbishment. London UK: Earthscan; 2010 Solar thermal devices & systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Solar domestic hot water system (SDHW) Introduction Hot Out Drainback tank Building refurbishment T Solar preheat tank Solar collector Assessment & evaluation Heat exchanger Controller Auxiliary tank T Material science Pump Pump Cold In Modern technology Renewable energy Cost control Applied from: Laughton Ch. Solar domestic water heating. London UK: Earthscan; 2010 Solar thermal devices & systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Solar domestic hot water system (SDHW) Introduction Building refurbishment SDHW systems are divided into two primary categories: direct and indirect. In direct or open-loop systems, water is directly heated through the solar collectors Assessment & evaluation Material science Drainback systems are examples of indirect and active SDHW. The main feature of a drainback system is the fail-safe setup used to ensure that the collector loop system, including the collector and the pipes, would not freeze by removing water from the loop when the system is not collecting solar heat Modern technology Renewable energy Cost control SDHW systems can use passive (i.e., natural convection) or active strategies (i.e., pump) to circulate water from the collector to the tank Applied from: Laughton Ch. Solar domestic water heating. London UK: Earthscan; 2010 Solar thermal devices & systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Solar integrated roofing systems Building refurbishment Photovoltaic panels Roof duct Heat collection/ glass panels For greater heating season collection, the angle should be the altitude + 15° (more vertical) and for cooling season collection altitude – 15°. These angles are general for early design development and should be refined through a more rigorous analysis to determine the optimum tilt angle Heat collection/ sheet-metal roofing Assessment & evaluation Material science Modern technology Renewable energy Cost control Roof air flow channel Air inlet Applied from: Hall MR. Materials for energy efficiency and thermal comfort in buildings. Cambridge UK: Woodhead Publishing Ltd; 2010 Solar thermal devices & systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Solar water heating system – sequence of functional groups Introduction Building refurbishment Solar radiation External solar collector Assessment & evaluation Cold water supply Pipes Material science Electricity for pumps and controls Water storage tank of solar heat Controls for safety, efficiency and information Modern technology Renewable energy Cost control Domestic hot water distribution system Back-up heating Applied from: Laughton Ch. Solar domestic water heating. London UK: Earthscan; 2010 Solar thermal devices & systems 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Building refurbishment Assessment & evaluation DarrieusRotor ‘Small’ means wind machines that are scaled from a few Watts to 20 kW. Machines between 1 and 5 kW may be used to provide either direct current or alternating current S-Rotor Material science Vertical versions operate at lower wind speeds and they are less stressed mechanically by turbulence. They can be sited on roofs or walls Modern technology Renewable energy Cost control Spiral Flugel rotor Applied from: Smith PF. Eco-refurbishment. A guide to saving and producing energy in the home. Oxford UK: Architectural Press; 2004 Wind energy for homes 1 2 3 4 5 6 7 8 9 10 11 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Building refurbishment Systems under 2 kW usually have a 24–48 V capacity aimed at battery charging or a DC circuit rather than having grid compatibility Assessment & evaluation Lange turbine HDarrieusRotor Material science Because of high turbulence caused by buildings, vertical axis machines are better than horizontal versions Modern technology Renewable energy ‘Aeolian’ roof devised by Altechnica. Wind turbine shown is Altechnica Wheel Darrieus cross flow wind turbine Cost control Applied from: Smith PF. Eco-refurbishment. A guide to saving and producing energy in the home. Oxford UK: Architectural Press; 2004 Wind energy for homes 12 13 14 15 16 17 18 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Geothermal systems Introduction Heat exchange loops Building refurbishment Assessment & evaluation Vertical Material science Heat exchange loops A typical GSHP system uses only electricity to power a pump and can be as much as 300 to 400% more energy efficient than a highly efficient furnace Modern technology Renewable energy Cost control Horizontal Applied from: Langnish O, Seyboth K. Paris FE: International Energy Agency; 2007 Heating pumps 12 13 14 15 16 17 18 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Geothermal systems Introduction Building refurbishment Ground-water Assessment & evaluation Material science Two wells Modern technology Renewable energy Cost control Thermoactive foundations offer a distinct advantage over conventional borehole systems Since concrete has a higher thermal conductivity than soil, thermoactive foundation systems are typically more energy efficient than the conventional geothermal heating pumps Applied from: Langnish O, Seyboth K. Paris FE: International Energy Agency; 2007 Heating pumps 12 13 14 15 16 17 18 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Diagram of a micro-CHP system Introduction Waste heat Building refurbishment Reject heat Prime mover Assessment & evaluation Absorption chiller Heat exchanger Desiccant device Heat exchanger Building cooling Building heating Building humidity control Hot water Generator Material science Electrical power Modern technology Renewable energy Cost control Combined heat and power generation, or cogeneration, is a well established concept dating back to the 1880s when steam was a primary source of energy in industry and electricity was beginning to be used for both power and lighting Applied from: Chamra LM, Mago PJ. Micro-CHP power generation for residential and small commercial buildings. New York NY: Nova Science Pub; 2009 Micro CHP power generation 12 13 14 15 16 17 18 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting CHP base technologies Introduction CHP base technologies CHP power generation technology Power range (applied to CHP) Power efficiency range (%) CHP efficiency (peak) (%) CCGT (Combined Cycle Gas & Steam turbines) 20MW – 600 MW 30 - 55 85 Gas turbine 2 MW – 500 MW 20 - 45 80 500 kW – 100 MW 15 – 40 75 5 kW – 10 MW 25 - 40 95 30 kW – 250 kW 25 - 30 75 Fuel cell 5 kW – 1 MW 30 - 40 75 Stirling engine 1 kW – 50 kW 10 - 25 80 Building refurbishment Assessment & evaluation Material science Steam turbine Reciprocating engine Modern technology Micro-turbine Renewable energy Cost control Applied from: Beith R. Small and micro combined heat and power (CHP) systems. Cambridge UK: Woodhead Publishing Ltd.; 2011 Micro CHP power generation 12 13 14 15 16 17 18 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction Renewable energy production options Building refurbishment INPUT Assessment & evaluation OUTPUT Renewable energy source Energy conversion system Direct useful heat Electricity generation or other energy carrier Material science Useful heat from CHP Modern technology Renewable energy Cost control Applied from: Langnish O, Seyboth K. Paris FE: International Energy Agency; 2007 Design principles for RES installations 12 13 14 15 16 17 18 Back Next Module 5: Renewable energy systems Learning Unit: Application of RES in building retrofitting Introduction i Building refurbishment To use renewable heat most efficiently from a quality perspective it is possible to set up a merit order of preference, although this may often differ from an economic point of view Assessment & evaluation 1. Energy efficiency and conservation options in buildings and industry sectors. 2. Passive solar heating building designs. 3. Solar thermal or geothermal where sufficient resources exist. 4. Geothermal heat pumps where possible, powered by renewable electricity. 5. Biomass in integrated bioenergy systems for cogeneration of electricity and heat 6. Biomass combustion, incineration and anaerobic digestion with the biogas used for heat only production Material science Modern technology Renewable energy Cost control Heating i Cooling Based on similar considerations the following merit order of preferred cooling technologies emerges 1. Energy efficiency and conservation options in buildings 2. Passive cooling options, summer night ventilation without the need for auxiliary energy. 3. Passive cooling options using auxiliary energy, e.g. cooling towers, desiccant cooling, aquifers. 4. Solar-assisted, CSP or shallow geothermal all driving active cooling systems. 5. Biomass integrated systems to produce cold 6. Active compression cooling and refrigeration powered by renewable electricity Applied from: Langnish O, Seyboth K. Paris FE: International Energy Agency; 2007 Design principles for RES installations 12 13 14 15 16 17 18 Back Next Module 6: Cost control Introduction Building refurbishment Assessment & evaluation Material science Modern technology Learning objectives. To give: 1. knowledge on costs planning and risk management for building renovation projects; 2. knowledge on uncertainty in refurbishment investment, costs of green buildings, financial benefits of green buildings, costs optimization. Renewable energy Cost control Back Next Module 6: Cost control Learning Unit: Uncertainties in investment, costs of green building, costs optimization Introduction Building refurbishment The reduction in energy costs depends on two highly uncertain inputs such as the fluctuating energy costs and forecasting building performance Assessment & evaluation NZER buildings are exposed to uncertainties in costs and benefits throughout their life cycle. Thus, a life cycle perspective is appropriate to identify and classify the uncertainties that characterize NZER during the design, construction, operation, and maintenance phases of the building Material science Modern technology Uncertainties are classified into two categories Internal External Internal uncertainties are internal to the NZER project and are within the control/decision of the building stakeholders External uncertainties are those beyond the control of the building stakeholders Renewable energy Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Uncertainties & risk management 1 2 3 4 5 6 7 Back Next Module 6: Cost control Learning Unit: Uncertainties in investment, costs of green building, costs optimization Life Cycle Uncertainties: Introduction Construction phase uncertainties Building refurbishment Design phase uncertainties Assessment & evaluation - forecasting weather conditions predicting energy savimgs predicting equipment performance and costs offsite generation prices of renewable energy predicting occupancy energy use characteristics fluctuating energy costs availability of space - Material science - Modern technology - Renewable energy Cost control - scheduling uncertainties budget and financing decisions preexisting conditions material functional characteristics integration of new and old building systems Operation and maintenance phase uncertainties - actual benefits of the refurbishment non-energy cost savings or benefits whole building performance revenue from building operation operation and maintenance costs performance of renewable energy systems future demand and supply of energy Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Uncertainties & risk management 1 2 3 4 5 6 7 Back Next Module 6: Cost control Learning Unit: Uncertainties in investment, costs of green building, costs optimization Introduction risk management elements that underpin the business case of investing in sustainable refurbishment of commercial buildings: Building refurbishment Assessment & evaluation Material science Modern technology Renewable energy Cost control • reducing potential risks to future income flow, depreciation and liquidity; • reducing risks to future funding and financing; • reducing risks with regard to changing occupier behaviour; • reducing risks resulting from a future legislative environment NZER risk management process Identify and classify uncertainties and risks Evaluate risks and uncertainties Use proper management tools Initiate risk management process Accept or manage risk Manage Review risk Accept NZER risk management process Monitor risk Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Uncertainties & risk management 1 2 3 4 5 6 7 Back Next Module 6: Cost control Learning Unit: Uncertainties in investment, costs of green building, costs optimization Costs Introduction Building refurbishment the costs of a remedial action at a time t (months or years): they comprise initial investment costs and annual costs, including running costs, periodic or replacement costs for repair or change of components and systems: Assessment & evaluation running costs comprise maintenance costs, operational costs, energy costs and added costs maintenance costs are annual costs for preserving and/or restoring the desired quality of the installation Material science energy costs are annual costs for energy and include all the charges listed in the energy bills Modern technology The reuse of the majority of an existing building’s fabric and an improvement to the building’s services and performance may result in the reduction of the overall environmental impact when compared to a new build Renewable energy Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Costs of green buildings 1 2 3 4 5 6 7 Back Next Module 6: Cost control Learning Unit: Uncertainties in investment, costs of green building, costs optimization Value based decision Introduction The reuse of an existing asset Building refurbishment A better balance of risk and return Quick delivery back to market (or refurbish whilst in use). Depending on the level of refurbishment, it is approximately 15–70 per cent quicker than new build Assessment & evaluation Maximisation of the value of an existing asset. With refurbishment, the developer is in the position where the unique style and character of an older building can be retained Refurbishment enables a developer to achieve the following: Material science Operational savings whilst re-energising the asset Creation of an opportunity to support new ways of working Modern technology Potential reduction of the carbon footprint of an existing building Refurbishment can avoid the reconstruction of major structural elements and still retain the benefit of the creation and provision of new office space. Depending on the level of refurbishment, the cost of the refurbishment is approximately 10–75 % less than new build Renewable energy Cost control Applied from: Burton S. Sustainable retrofitting of commercial buildings. Cool climates. Oxon UK: Routlege; 2015 Costs of green buildings 1 2 3 4 5 6 7 Back Next Module 6: Cost control Learning Unit: Uncertainties in investment, costs of green building, costs optimization Strategic value to NZER (Nearly Zero Energy Refurbishment) Introduction Definitions Building refurbishment Option to stage The refurbishment project is divided into stages. At the end of each completed stage, the costs/benefits are evaluated to determine whether subsequent stages can be pursued or not Option to abandon Terminate the refurbishment before completion and dedicate resources to other projects Assessment & evaluation Material science Modern technology Renewable energy Cost control Option to defer Postpone the refurbishment without jeopardizing the potential benefits Option to grow Provides an initial baseline that allows the stakeholder to pursue follow-on opportunities Option to reduce Reduce the magnitude of the refurbishment and save costs Option to switch Developed assets can be switched or redeployed to serve another purpose Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Costs optimization – options category 1 2 3 4 5 6 7 Back Next Module 6: Cost control Learning Unit: Uncertainties in investment, costs of green building, costs optimization Strategic value to NZER (Nearly Zero Energy Refurbishment) Introduction Application to investments in NZER Building refurbishment Assessment & evaluation Material science Option to stage The refurbishment is divided into stages depending on available budget. First stage might involve installation of PV systems to achieve energy balance. And the second stage could involve major renovations of HVAC equipment Option to abandon An exhaustive feasibility study of the existing building condition might indicate that the associated incremental costs to NZER are too high. The building stakeholders might abandon the project Option to defer The decision to invest in NZER can be deferred until debt financing becomes available at attractive rates to the owner, or until the tenants can arrange to lease alternative space for the duration of the refurbishment project Option to grow The owner of can decide to invest in one NZER as a pilot project and decide to expand refurbishment work to the remaining of his/her existing building stock once perceived benefits from NZER the pilot project outweigh the costs incurred Option to reduce Reduce the scope of the NZER endeavor when the costs of the refurbishment exceed the allocated budget. Other scheduled energy-efficient replacements or updates for the building will need to be postponed or forgone all together Option to switch Stakeholders of a commercial building might decide to switch the tenant occupancy of certain floors from three to four tenants per floor to only one tenant per floor to be able to satisfy the market needs Modern technology Renewable energy Cost control Applied from: Torgal FP, at al. Near zero energy building refurbishment. London UK: Springer-Verlag; 2013 Costs optimization – options category 1 2 3 4 5 6 7 Back Next Congratulations! You have completed a Course on Energy Efficient Renovation of Old & Historic Buildings CLOSE