Cumbria Rural Housing Trust
Redhills House, Redhills Penrith, Cumbria, CA11 0DT
Tel. 01768 210265
www.crht.org.uk
A guide to sustainable construction
Efficient methods - Better homes
Opportunities for communities, local authorities and housing providers
Innovation in Planning, Design and Costs
Howels Farm Dartmoor
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Affordable home in perpetuity
Self-built & managed
Parents land
Timber frame
Wood burner + solar thermal
Western red cedar
Introduction
Heightened awareness of global warming means that more people appreciate that
the design of buildings and choice of materials can help to reduce CO2 emissions
and running costs. Especially as buildings and building materials are responsible
for over 50% of UK greenhouse emissions.
New homes only make up about 2% of the national housing stock so the main
challenge is to improve the mass of older housing. However new homes present
an easy opportunity to build with minimal environmental impact and maximum
health benefit. This has been recently formalised in the new Code for Sustainable
Homes and in the tightening of building regulations.
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The potential to do well
The Commonwealth Scientific and Industrial Research Organisation
18 tonnes of carbon released by materials used in each new home
2.5 tonnes per home annually for space heating
197,902 new homes in 03/04 representing 3,562,236 tonnes of carbon released.
‘This contrasts with very low levels of embodied energy used in sustainable
construction such as timber frame, and very low heating requirements that also
impact on fuel poverty’.
Build It magazine Heating Report, December 99
Making best use of the new technology, we can:
Virtually eliminate the need for space heating
Reduce water heating by 65%
Reduce energy for cooking by 60%
Reduce energy used by electrical appliances by 80%
Reduce energy used for lighting by 85%
The overall impact of these could be enough to reduce fossil fuel use and
CO2 emissions by 95%."
Housing and health
Choice of materials can have profound environmental and health consequences.
PVC - Austria banned the use of PVC, as have many corporate manufacturers,
due to the phthalate environmental poisons produced in manufacture and it has
toxicity in house fires (See materials descriptions below). Yet a study by Carlisle
City Council found that UPVC windows were 25% more expensive, but less
durable & higher maintenance than quality timber frame windows.
Sunlight - Designing homes with more natural light increases psychological
wellbeing and reduces lighting and heating demand. See book list.
So whether renovating, planning an extension or involved in the provision of new
buildings, your choices matter.
The 6 aspects of sustainable construction:
Rab Bennetts Associates, designers of the Wessex Water HQ, Bath
1. Reducing operational energy - energy consumed during the building’s lifetime,
(90%)
2. Reducing embodied energy - energy used to produce the materials, (10%)
3. Reducing transportation energy - how far the products are brought
4. Reducing waste energy - during build and during use
5. Increasing the biodiversity of the site once in use
6. Ensuring the health & social interaction of people using the site
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Focus on affordability
Sustainable construction can be interpreted in more or less complex ways and
costs can vary hugely, so it is important to work with partners know how to
control cost as well as produce sustainable design.
Insulation: This is the single most important factor leading to sustainable
construction (the tea cosy) as most energy is consumed for space heating during
the lifetime of the building. With the right advice it is not difficult to build
sustainably for the same price or less than conventional build. Where ‘pure’
methods such as all timber prefabrication can be applied economies will be gained
including quality control, speed of construction, lighter cheaper foundations
(ground excavation and concrete foundations are expensive, whereas point
foundations are cheap and allow ground water to soak away) and negligible use
of fossil fuel processed materials. These methods are already accepted by
building control.
Sustainable costs
New methods matter:
Sustainability means delivering buildings that are in harmony with health and the
environment and cost less to run by introducing natural light and solar gain but
are also affordable to construct.
Costs can vary greatly according to the build specification, build method and how
materials are procured – some schemes have created savings by using local
timber, others are obtain cost stability by working with timber frame
manufacturers – costs can be as low as £50,000 with free land and a very hands
on self build, to around £120,000 on exception site land (land for rural affordable
housing sold at modest value) delivered by professional contractors. Be clear
about whether you are being quoted build cost only or whole scheme cost
including land and services etc.
Cost headings
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Land - free or modest value for affordable housing
Professional fees – conveyancing / design / / contracts / planning
Approach to delivery – self build / semi self build / local builder / design &
build company etc
Services and access
Foundations & build method
Choice of energy systems
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Energy and heating choices
Choice of appropriate heating and power systems will affect scheme affordability.
Space heating: A home insulated to modern or super insulation standards will
require virtually no space heating at all enabling capital savings to be made
through avoidance of central heating systems. Low power electric heaters in
urban locations, or a small wood stove in rural locations will be more than
sufficient to provide reassurance in the depths of winter. Technology such as
ground source heat pumps represent an unnecessary cost for well insulated new
build, but are well suited to heat existing older buildings.
Hot water: Solar water heating panels can save a household 70% of water
heating bills and are cost effective at around £3,000 per home depending on
make. Further significant domestic energy costs will be saved through installation
of modern condensing boilers.
Electricity: Experts at the Centre For Alternative Energy point out that, for all
but the most isolated locations, the most cost effective way to access green
electricity is to hook up to the national grid and sign up to a green utility
company. Unless 100% grants are available, energy independence via photo
voltaic panels or windmills is incur extra costs likely to threaten the financial
viability of affordable housing schemes. As items such as fridges consume the
most power, electricity consumption can be reduced through use of efficient white
goods.
Combined heat and power: Both gas and solid fuel boilers are available that
act as miniature power stations making both heat for hot water and space, and
electricity to power the home. The cost and practical requirements for this
technology need to be appropriate for the scheme in question, for instance in
terms of storage space for wood chips, and maintenance. This technology would
seem well suited to older buildings, or new neighbourhood schemes.
Schemes that are leading the way
Falcon Rural Housing Association:
Falcon Rural Housing Association homes at Nether Stowey, Somerset
Most Housing Associations using conventional build methods expect the new Code
for Sustainable Homes to add to the already high cost of development to the tune
of around £8,000 per home. Using different methods Falcon Housing Association
based in Somerset are exceeding the code standards for no extra cost. This is
because Falcon uses modern timber energy efficient homes made by Merlin
Timber Frames. The homes are very popular with residents and Sedgemore
District Council. Locations in Somerset.
Contact Justin Roxburgh, Falcon House, 3a South Street, Wellington, Somerset,
TA21 8NR, 01823 667343
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Community innovation:
Worth Matravers & Buckland Newton Community Land Trusts, Purbeck & West
Dorset.
The two separate communities decided to set up Community Land Trusts to
provide additional affordable homes without Social Housing Grant. This is being
achieved by combining local procurement with modern methods of construction
and low land value associated with Rural Exception Sites policy. This will also
enable added saving from rapid construction time and produce homes with very
low running costs. The scheme for 10 units at Buckland Newton will go on site
this year. The District Council has provided small grants and favorable lending for
the development phase. Use of straw bale insulation will trap carbon into the
structure rather than release it into the atmosphere as with conventional
materials such as brick. Expected build & infrastructure cost c £800 to
£1,000m2.
Point foundations save money and ground disturbance and meet building regulations.
Contact ARCO2 architects.
01208 832990 www.arco2.co.uk
info@arco2.co.uk
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Self-build in Cornwall - Organisations working together:
With the support of North Cornwall District Council, Cornwall Rural Housing
Association is helping communities to develop self built affordable homes, which
will be owned by their own community land trusts. The homes will meet level
three of the new Code for Sustainable Homes. The schemes will also be
augmented with social rented housing provided by the Housing Association - all
strictly to meet local need – as it is currently easier for CLTs to provide shared
ownership homes.
DVD available
Contact Alan Fox, Cornwall Rural Housing Association Limited
1 Dreason Barns, Bodmin Road, BODMIN, Cornwall, PL30 4BG
Telephone: 01208 264530
Bigger builders:
Integer Partnership has developed sustainable affordable housing at Lyttleton
Street, Lyng Estate, Sandwell. Sandwell Metropolitan Borough Council wanted to
use INTEGER to challenge the perceived mediocrity in current homebuilding
practice, and so increase the expectations of the public regarding social housing.
Achieving change in housing is difficult. The industry is complex, with a wide
range of different stakeholders and a high level of structural inertia. Customer
expectations have traditionally been low, and there have been few incentives to
innovate. To engineer change, it is necessary to involve as many of these
stakeholders as possible in a win-win, low risk programme of applied innovation.
This is precisely what INTEGER offers.
INTEGER (Intelligent and Green) Limited, Building 9, Bucknalls Lane, Garston,
Watford, WD25 9XX. Tel. 01923 665955. Email: integer@integerproject.co.uk
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Government policy
Since the Kyoto Agreement, government has gradually moved towards reducing
the environmental impact of building design and materials in the drive to
moderate the consequences of global warming.
This is reflected in various policies & initiatives such as:
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Annual changes to the building regulations regards insulation
Landfill tax
Publication of government strategy in "Building a better quality of life"
The Egan Report 'Rethinking Construction'
Establishment of the Housing Forum.
And recently:
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Sustainable Buildings Task Group report to Office of the Deputy Prime
Minister
Revised Planning Policy Statements such as PPS1 and PPS22 regarding
sustainable development and renewable energy
The Sustainable and Secure Buildings Act
The Sustainable Development Commission, which covers building design.
Target for Zero Carbon housing 2016
Zero Carbon housing consultation paper
The new Code for Sustainable Homes
Materials & Design
Timber
Timber is one of the most versatile building materials used around the world,
having the advantage of being "carbon neutral". This means it releases the same
amount of carbon back into the atmosphere when burned or decomposing that
was taken up whilst growing. Timber can also be dismantled and re-used.
Timber such as Western Red Cedar continues to be sourced indiscriminately by
timber importers & builders merchants from old growth forest and has lead to
habitat destruction and loss of topsoil in famous instances such as Madagascar.
The recent introduction of accredited FSC timber (Forestry Stewardship Council)
means that timber bought in this way should come from forests managed
sustainably, harvesting by selective felling as practised in rather than clear felling.
Sustainable timber can be acquired from countries such as Finland, Sweden,
Canada and the UK.
Imported Scandinavian softwood provides the main material used for off-site
manufacture of housing from sustainably grown and harvested. Meanwhile the UK
has large quantities of quality building timbers such as Western Red Cedar (self
preserving) and Douglas Fir, which need local markets.
Timber systems have the benefits of speed, precision and subsequent low running
costs of the housing. These benefits are maximised where timber is accepted as a
finish as well as a structural frame. The lighter structure means the use of
concrete for foundations is minimised resulting in reduction of overall costs, or
redirection of funds into other components such as higher insulation values. Costs
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can be the same as conventional 'wet trade' methods, or lower. Savings can be
even greater when using local materials depending on the experience of those
involved and the approach to contracting.
Straw bale
Torfaen County Borough Council industrial estate pilot.
Straw bale is durable and fireproof if constructed correctly and ‘sequesters’
carbon into the building instead of releasing it into the atmosphere. American
timber frame buildings insulated with straw bale built in the 19th century are still
used and in good condition. Bale can be used as load bearing (Nebraska style) or
infill within timber frame, or as insulation within a modern timber frame – as to
be used for the Buckland Newton affordable housing scheme in West Dorset.
Buckland Newton specialist contractor: www.dorsetruralskills.co.uk/
Architects: www.arco2.co.uk/ - also classrooms
Cumbria successful planning application: http://brianwaite.co.uk/strawhouse.html
Cumbria National Trust project: www.nationaltrust.org.uk/main/w-global/wlocaltoyou/w-northwest/w-news-projects-st_catherines_footprint.htm
Planned largest UK straw bale building: www.collinsandbeckett.co.uk/
Rammed earth
Stabilised Rammed Earth stable block, Northants.
Built 2001 from www.earthstructures.co.uk
Stabilised rammed earth can have the
appearance of cut stone, the strength of
concrete and the weather resistance of
brick; yet environmentally outperform any
of these.
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Lyme hemp
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encases structural timber frame, which can be untreated
medium thermal mass
single skin construction
carbon negative, locks up CO2
breathing wall construction
From Powerpoint by Colin Savage, Rural Housing Enabler, Exmoor, North Devon and West Somerset
Rural Housing Project cbsavage@exmoor-nationalpark.gov.uk
Other materials & methods:
Cob; Recycled tyres (earthships)
Less desirable materials
PVC
From Building for a Future magazine: The Austrian Supreme Court classed PVC as
"an environmental poison". 60% of poly vinyl chloride is produced for use by the
construction industry. Chemical phthalates contained in PVC leak out and are
banned from certain baby toys in the UK.
The Department of the Environment, Transport & the Regions states, "There is
concern about the environment and health effects of PVC. One of the concerns is
the health risk posed by phthalates, which are oestrogenic chemicals that mimic
naturally occurring hormones. Food packaging is one area of concern but
substances can get into the environment by a variety of sources."
Newhaven Council are phasing out the use of PVC in their building stock. In
addition, Nike, Volvo and Ikea are taking steps to minimise the use of PVC in their
production lines. Alternative plastics are available.
In addition to the chemical content, PVC also contains heavy metal fillers such as
cadmium and lead. All of these materials give rise to concern about the potential
harm in the case of house fires.
Architects John Gilbert of Glasgow includes the following points on PVC in their
report on the material: PVC is created using Chlorine gases, which are highly
toxic. The production process creates highly toxic waste, including dioxin and
organ chlorines. These waste products can find their way into watercourses and
thence into the food chain. There is strong evidence that in fires, PVC will give off
volumes of toxic fumes including dioxin emissions.
Cement
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Cindy Harris, designer of the Antonymous Information Centre at the Centre for
Alternative Energy writes "Cement manufacture is very polluting and is
responsible for between 7% & 10% of all global Co2 emissions. This high figure
is the result of a "double whammy" - firstly the ingredients have to be heated to
very high temperatures (1500c), which takes a lot of fossil fuels; secondly the
chemical reaction which takes place in the kiln also releases Co2. "In addition, all
the big cement companies are now burning Secondary Liquid Fuels which are
composed of hazardous wastes.
These are being burnt in less stringent
conditions than would apply for licensed hazardous waste incinerators, and this
practice is probably releasing extremely toxic pollutant into the atmosphere. In
contrast lime mortar re-absorbs all the Co2 which was driven off in the kiln."
There is also the question of the mess and damage caused to the building land
during construction and the delays for drying out plus damp present in the new
structure. Drying is slower with lime mortar.
Conventional Paints
Paint industry products produce the same quantity of green house gasses as the
whole of Britain's traffic each year. This includes many water-based paints where
the relevant chemicals are released at the manufacturing stage. Chemical
thinners are released into the environment during manufacture and application
affecting the environment, trades people & occupants. Organic non-toxic paints
are a small factor of the overall construction cost. It is also possible to use
materials, which do not need to be painted.
Brick
Whilst brick is a very versatile material, it is produced by burning fossil fuels in
kilns, which produce large amounts of Co2. Added to this is the environmental
impact of quarrying the clay. On the other hand, because brick is very durable it
is possible to recycle it to be used again.
Stone
Stone is a very expensive material, which can have the effect of drastically
inflating the overall cost of a building. It is associated with the environmental
impact of quarrying unless recycled stone is used.
Other issues
Electro-magnetic pollution
Homes can be designed to minimise exposure to electrical fields generated by
conventional domestic ring mains. The ring mains create a magnetic field around
the home, which is associated with 'sick building syndrome'. Cable arrangements
based on spurs, or switching off the supply in sleeping areas will avoid this. Ref.
Living Spaces, see publications.
Condensation
The use of modern impervious materials combined with air tightness of windows
etc allows moulds to flourish with subsequent effects on health. (Building for a
Future magazine 2005) Good design involves use of breathable materials that
avoid condensation combined with passive ventilation systems and increased
natural light, which helps to kill bacteria and mould
Demolition & Waste Disposal
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The statistics for Somerset show that brick & concrete rubble account for 60% of
the counties landfill requirement, 1.5 million tons per annum at a cost of around
£35 per ton to dispose of. The Government wishes to see a 70% reduction of
landfill by 2010. In Denmark 82% of aggregate used in road building/foundations
etc is recycled from demolished buildings & torn up roads. In Britain 10% of
demolition, waste is recycled.
Sources of information, materials & support
If you are involved in construction projects, you can locate a wide range of
construction professionals supportive of sustainable construction by searching on
the internet or enquiring through your local Agenda 21. This guide contains some
points of contact as follows.
The Code for Sustainable Homes
The Department for Communities and Local Government (DCLG)
Sustainability in construction is primarily determined through evolving Building
regulations. Applying the Code above is optional for private schemes whilst
Housing Associations are required to build to level three by the Housing
Corporation. This may or may not incur extra costs according to the build system
chosen. DCLG say,’ The new requirement to have a rating against the Code does
not make it mandatory to build a Code home or to have each new home assessed
against the Code. It does however mean that all buyers of new homes be given
clear information about the sustainability of the new home.’
http://www.communities.gov.uk/planningandbuilding/buildingregulations/legislati
on/englandwales/codesustainable/
The Centre for Alternative Technology
Europe’s original leading eco-centre. State of the art eco-information centre,
consultancy, school visits, courses, publications and products.
CAT, Machynlleth, Powys, SY20 9AZ, UK www.cat.org.uk Education: 01654
705983 Courses: 01654 705981 Shop: 01654 705993
The Somerset Trust for Sustainable Development
Contacts and advice on sustainable construction. National conferences. Annual
'Homes for Good' exhibition.
The
Town
Hall,
Bow
Street,
Langport,
Somerset,
TA10
9PR.
www.sustainablehousing.org.uk Tel. 01458 259400
Ecology Building Society – mortgages and insurance
7 Belton Rd, Silsden, Keighley, West Yorks, BD20 0EE
Tel. 0845 6745566
email:info@ecology.co.uk
Website: www.ecology.co.uk
Bradfords Builders Merchants
Can supply eco-rated materials
Rod Hughes
Ad hoc associates architecture+sustainability
Bankview, Penruddock, Cumbria, CA11 0QU Tel/Fax 017684 80313
ARCHITYPE eco-architects
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Contact Jonathen Hines, Belle View Centre, Cinderford, Gloucestershire, GL14
2AB Tel. 01594 825775 www.architype.co.uk
District Council HECA Officers
Heating Energy Conservation Officers
Agenda 21
Local action group all issues connecting with sustainability.
Redhills Business Park, Unit 5B, CA11 0DT, 01768 210276
www.edenla21.org.uk
Taunton College
The Genesis Centre: a contemporary construction education centre which itself
will be built using sustainable materials such as timber, earth and straw bale.
Designed by Jonathan Hines of Archetype, Genesis will serve the Western region
and the whole country as an educational resource centre of sustainable building
technologies, both modern and traditional. www.genesisproject.com
Publications
Building for a Future magazine
The Association of Environmentally Conscious Builders – Informative professional
magazine. Also Green-pro services & materials directory & The Real Green
Building Book directory of affiliated professionals.
Green Building Press, Box 32, Llandysul, SA44 5ZA, www.newbuilder.co.uk
Sustainable construction information sheet
The Chartered Institute of Builders
www.cbcscheme.org.uk/cbcscheme/ publications.aspx
Timber frame construction manual
TRADA - The Timber Research & Development Association
Living Spaces
Ecological Building & Design – Excellent German / American reference book by
Gunter/Abraham/Fisher
Simply Build Green
John Talbot (A Technical Guide to the Eco Houses at the Findhorn Foundation)
The Whole House Book
Borer & Harris
Planning for Sustainable Construction & Development
A guide to positive planning for the 21st century - Somerset Trust for Sustainable
Development
The Healing Sun
Prof Richard Hobday. The Merits of Getting Sunlight into Buildings.
Selected web sites
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Building Research Establishment – Ecohomes standard.
www.bre.co.uk
Integer web site resources list & Integer house illustrations
www.greenspec.co.uk/html/resources/resourcescontent.html
World Wildlife Fund campaign for 1 million sustainable homes
www.wwf.org.uk/sustainablehomes/index.asp
The Association of Environmentally Conscious Builders
www.aecb.net
Hastoe Housing Association database of sustainable construction schemes
www.sustainablehomes.co.uk
www.sustainableconstruction.co.uk
The Sustainable Construction Site
Wren & Bell Structural Consultants
Reports include performance of PVC in fires
Britain’s first eco property web site allowing buyers to make an informed choice
and do their bit for the environment.
www.greenmoves.co.uk
The Forestry Commission
www.forestry.gov.uk
Wood for Good
High quality portal for timber importers offering detailed information on all
aspects of timber and construction.
Woodforgood.com
Tel 0800 279 0016
Eco-cement & eco-inventors
www.abc.net.au/newinventors/txt/s1296184.htm
UK straw-bale building database
www.strawbale-building.co.uk
www.greenbuilder.co.uk
Green architects
www.forevergreen.org.uk
Eco materials & professionals links
http://theyellowhouse.org.uk/themes/address.html
Timber frame manufacturers (ask about FSC accreditation)
www.project-builder-insurance.com/tf.htm
Author: Andy Lloyd
Community Land Trust Project Officer
Cumbria Rural Housing Trust
Redhills House, Redhills Penrith, Cumbria, CA11 0DT
Tel: 01768 210265
Mobile: 07525688662
andy@crht.org.uk
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