Zero Carbon House
Worcester Zero Carbon House:
This project is to design a new zero carbon house
located near the centre of Worcester. The building is to
be largely self-sufficient in terms of its services and
energy usage and is to conform to Level 6 of the Code
for Sustainable Homes (CSH)
Aims & Objectives:
The team has been appointed to develop the project from a
conceptual design stage to Stage D of RIBA plan of work. This
entails producing a detailed tender proposal with careful
consideration to specific elements such as:
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Structure:
Modularised straw bales to act as load bearing walls.
Steel Column and Beams
Conventional pitched roof trusses - fibre reinforced polymer (FRP).
Curved concentric “Armadillo roof” trusses
Glued laminated timber (GLULAM).
Code for Sustainable Homes:
The CSH provides the national standard for assessing the
environment performance of the design and construction for new
homes. It encourages greater innovation and continuous
improvements in sustainable home building practice. The Code is
currently not mandatory, but the government has set targets that
all new homes must meet a zero carbon standard by 2016 –
Code Level 6.
The CSH uses a rating system represented by ‘stars’ ranging
from one to six . One star is the entry level – above the level of
the Building Regulations and six stars is the highest level and
mark of quality and indicates a ‘zero carbon home’.
The Code measures the environmental
impact of a home against nine design
Foundations:
Foundations made from Novacem carbon negative cement.
Cement absorbs 100kg of CO2 per tonne of cement produced.
Performance and cost similar to Portland cement.
Foundation based on a stiffened edge raft.
Thicker at points of loading: below loadbearing walls and columns.
Energy / CO2
Water
Materials
Surface water run-off
Floor Plan:
Waste
Pollution
Health and wellbeing
Management
Ecology
Air tightness strategy
Exploded View of Structure
Waste water treatment management
Roof Trusses
Mechanical Ventilation Heat Recovery (MVHR)
Passive heating and cooling design
Foundation and ground floor slab design
Loadbearing Walls
Solar Photovoltaic & Water Heating
MVHR enables houses with a high air tightness to remove stale damp air inside and
replenshing with fresh, dry outside air with minimal heat loss.
Low embodied energy structure
Renewable energy strategy
This academic poster describes and illustrates the design
characteristics of our proposal, emphasising the architectural,
technological and functionality of the home.
Warm, moist air from bathrooms and the kitchen are extracted and
a heat exchanger (HEX) recovers heat.
Outside
Heat is transferred to the cold, dry outside air through
the HEX and are typically over 85% effective.
MVHR removes the need for opening windows and can be
reversed to provide cooling.
Bedrooms
Living Areas
Office
Bathrooms
Kitchen
Site ecology:
Foundations
50m2 south facing roof with 30° pitch
Solar Water heating can supply up to 60%
of hot water needs requiring an area of 5m2
4kW PV system requires area of 3m2
Electricity used immediately and remainder
is fed back into National Grid for payback
Panels are self-cleaning by rainfall
Using seedum improves ecology impact
Reduce surface runoff acting as a buffer
Rainwater harvested for outdoor usage
Provides additional thermal insulation
HEX
Columns and Beams
Becoming carbon zero requires meeting all electricity and heating
demands using renewable sources.
Green Roof
Warm, dry air is circulated by the Heat Exchanger through
ducting into rooms throughout the house.
Key areas of innovation
Two quarters for sleeping and living for noise reduction.
Open plan living area and curved window allow for a continuous
light source throughout the day.
Optimal daylight having east facing bedrooms, south facing
lounge and west facing dining room.
Based on Passivhaus design for improving energy efficiency.
Bathrooms and WC's placed adjacent for easy plumbing.
Utility and plant rooms orientated to ensure convenient delivery
access for wood pellets.
Ecoslate
The site currently comprise of predominately species-poor neutral
grassland and hedgerows. An external ecologists has suggested the
ecological impact of the site can be improved by:
100% Recycled PET plastic
Self-bonding using sun's heat
Better insulation compared to traditional slate
Lightweight (20kg/m2)
Easy to install with solar panels
50 year warranty
No maintenance
Growing native trees, coppice and hedgerow climbing species
Use of turf containing a mix of grass and flower species
The provision of three bat boxes and three bird boxes
Integrating green roof within the roof design
Lamb Wool Insulation
Rainwater Harvesting:
Derived from lambswool
100% Natural and sustainable material
100% Biodegradable
Absorbs 40% of Volume in moisture
Retains high U-Value for 50 Years
High thermal conductivity
Collecting rainwater helps supplement and reduce
dependancy on mains water for nonpotable uses.
Only 80L of water p/p per day can be used.
Rainwater is collected from roof (256m2)
Estimated water harvesting per year: 57600L
Effective through more than 3 weeks drought
Water is stored in a large tank (3600L)
Rainwater can be used for:
Washing machines, toilets and outdoor uses
Daylight Modelling
Rainwater Harvesting
Green Roof
Solar PV & Heating
Increasing daylight aims ‘to promote good daylighting and improve
quality of life and reducing energy to light the home’
Kitchens and Living spaces must achieve a minimum average
daylight factor (DF) of 2% and 1.5% respectively
Wood Pellet Biomass Boiler
Triple Glazed Windows
Preliminary energy analysis estimaed a 15kW boiler is required to meet
peak heating demand to supplement Solar Water heating.
'Passivhaus' design encourages large south facing windows to
increase 'solar gain'. The floor behaves as thermal mass storing solar
energy and dissipating heat throughout the day reducing heating
loads during Winter.
Daylight modelling has shown our kitchen design to achieve an
average of 11.3%
Good uniformity and over 80% of the working plane receives direct
light from the sky
High DF = possible overheating problems in the summer; this is
being addressed in our heating and cooling strategy
Prefabricated Straw Bale Wall
Exterior walls constructed from modular prefabricated load bearing compacted straw
bales. Straw is locally sourced and these offers superior properties:
Burning Biomas is carbon neutral
Wood pellets offer convenience will be stored in silos
and fed automatically into boiler.
Delivery required 2-3 times per year.
The RHI - Renewable Heat Initiative supported by
the Government provides extra payback.
Used in combination with underfloor heating
Thermal losses are reduced using triple glazing with
timber/aluminium frame: U = 0.63 W/m²K
Wood Box
Straw
Plaster
High thermal insulation: U = 0.13 W/m²K
Sound reduction: 50dB
Low embodied energy
Breathable - reducing damp
Prefabrication reduces construction time and damp
issues during construction
Great fire protection: 2hrs 15Mins
Hannah Rowland, Erin Dunn, Ashan Craig, Jonny Martin, Chris Goodwin, Will Jebb, Luke Parry, Emily Huynh
Prof. Toby Mottram, Kieran Gosling
Background reading: case studies,
materials and technologies
Initial concepts begun
In depth research on: solar PV and
water heating, triple glazing, green
roofs, ventilation, foundations.
Structural considerations:
spans, pitch of roof.
Week 2
Week 4
Drawing updated
Further roof research
Loading considerations
Roof material decided
Heating calculations and consideration
Week 6
Week 8
Structural Work Developed
Lighting Considered
Detailed design calculations begin:
Foundations
Structures
Energy calcuations via SAP
Academic poster
Week 10
Construction planning and on-site assembly.
Final SAP energy calculations
February
Week 16
April
Timeline
Week 1
Formation of group
Outline of plan for work
Week 3
2nd and 3rd iterations of house designs
presented.
Final floor plan drawing produced.
Week 5
Further technologies, energy and
materials research.
Week 7
Floor plan finalised
Roof designs and materials
developed
Week 9
Solidworks model produced
Insulation ideas developed
Week 15
Structural Work developed
CRM considered
Daylight modelling begun
January
Creation of one overall knowledge document
Finalisation of materials and technologies choice
March
Continuation of detailed design calculations
Waste conservation and waste water treatment strategies.
May
Final tender proposal submission
Tender presentation to client