- Energy efficiency in British housing
housingin the United Kingdompresents one of the major opportunities for achieving the 20% overall cut in UK carbon dioxideemissions targeted by the Government for 2010.
Although carbon emissions from housing have remained fairly stable since 1990 (due to the increase in household energy use having been compensated for by the 'dash for gas'), housing accounted for around 30% of all the UK's
carbon dioxideemissions in 2004 - 40 million tonnes of carbon [http://www.publications.parliament.uk/pa/cm200405/cmselect/cmenvaud/135/13507.htm#a23 House of Commons - Environmental Audit - First Report ] ] - up from 26.42% in 1990 as a proportion of the UK's total emissions. [http://www.statistics.gov.uk/StatBase/Expodata/Spreadsheets/D7280.xls] The Select Committee on Environmental Auditnoted that emissions from housing could constitute over 55% of the UK's target for carbon emissions in 2050.
A 2006 report commissioned by British Gas [ [http://www.britishgasnews.co.uk/managed_content/files/pdf/greenCity.pdf Domestic Carbon Dioxide Emissions for Selected Cities] , "British Gas", published 2006-02-20, accessed 2007-08-09] estimated the average carbon emissions for housing in each of the local authorities in
Great Britain, the first time that this had been done. This indicated that housing in Uttlesford( Essex) produced the highest emissions (8,092 kg of carbon dioxide per dwelling). This was 250% higher than than housing in Camden ( London) which produced the least (averaging 3,255 kg). Among the 23 towns included, Reading had the highest emissions (6,189 kg), with Hull the lowest (4,395 kg). The variations are due to a number of factors, including the age, size and type of the housing stock, together with the efficiency of heating systems, the mix of fuels used, the ownership of appliances, occupancy levels and the habits of the occupants.
Zero carbon ambition
In the December 2006
Pre-Budget Report[ [http://www.hm-treasury.gov.uk/pre_budget_report/prebud_pbr06/prebud_pbr06_index.cfm Pre-Budget Report 2006: Index ] ] the Government announced their 'ambition' that all new homes will be 'zero-carbon' by 2016 (i.e. built to zero-carbon buildingstandards). To encourage this, an exemption from Stamp duty land taxis to be granted, lasting until 2012, for all new zero-carbon homes up to £500,000 in value. [ [http://www.hm-treasury.gov.uk/budget/budget_07/bud_bud07_speech.cfm Budget 2007: Speech ] ]
Whilst some organisations applauded the initial announcement of the scheme, in the pre-budget statement from the then UK Chancellor, Gordon Brown, others are concerned about the government's ability to deliver on the promise. [ [http://www.newbuilder.co.uk/newsletter/december_06.asp Green Building ] ] [ [http://news.bbc.co.uk/2/hi/business/6214434.stm BBC NEWS | Business | New homes to be 'zero emission' ] ]
Domestic energy use
The housing stock in the United Kingdom is amongst the least energy efficient in Europe. [http://www.parliament.uk/documents/upload/postpn249.pdf] In 2004 housing (including space heating, hot water, lighting, cooking, and appliances) accounted for 30.23% of all energy use in the UK (up from 27.70% in 1990) [ [http://www.dti.gov.uk/files/file10738.pdf DTI] ] . The figure for
Londonis higher at approximately 37%. [ [http://www.jeanlambertmep.org.uk/ Jean Lambert Green MEP for London ] ]
In view of the progressive tightening of the Building Regulations' requirements for energy efficiency since the 1970s (see the history section below), it might be expected that a significant cut in domestic energy use would have occurred, however this has not yet been the case.
Although insulation standards have been increasing, so has the standard of home heating. In 1970, only 31% of homes had
central heating. By 2003 it had been installed in 92% of British homes, [ [http://www.dti.gov.uk/files/file17832.xls DTI] ] leading in turn to a rise in the average temperature within them (from 12.1°C to 18.20°C). [ [http://www.dti.gov.uk/files/file17841.xls DTI] ] Even in homes with central heating, average temperatures rose 4.55°C during this period.
At the same time, the increase in the number of households, increasing numbers of domestic electrical appliances, an increase in the number of light fittings, reduction in the average number of occupants per household, plus other factors, had led to an increase in total national domestic energy consumption from around 25% in 1970 to about 30% in 2001, and remained on an upward trend (BRE figures).
The figures for energy consumed by end use for 2003. [ [http://www.dti.gov.uk/files/file17822.xls DTI] ]
Space heating- 60.51% (57.61% in 1990)
*Water heating - 25.23% (25.23% in 1990)
lighting- 13.15% (13.4% in 1990)
*Cooking - 2.74% (3.76%)
The 1965 Building Regulations introduced the first limits on the amount of energy that could be lost through certain elements of the fabric of new houses. This was expressed as a u-value - the amount of heat lost per square metre, for each degree
Celsiusof temperature difference between inside and outside.
In effect the Target Insulation is a ration of 1.33 W/m^2/K of floor area (Document L 2006). So to keep your square metre warm you are limited as to how much energy you can use. This is slightly regressive in that richer people live in bigger houses which tend to have a lower surface area /floor area, although this is partially offset by them being detached.
These limits were tightened following the
1973 oil crisis, and on several subsequent occasions (see below. Despite this, UK insulation levels have remained low compared to the EU average. [ [http://www.locosoc.info/download/projects_management/interim%20report/Annex5%20-%20WP3.doc] ]
energy policy of the United Kingdomthrough the 2003 Energy White Paper [ [http://www.dti.gov.uk/files/file10719.pdf BERR - Redirect ] ] articulated directions for more energy efficient building construction. Hence, the year 2006 saw a significant tightening of energy efficiencyrequirements within the Building Regulations (for earlier regulations, see separate section below).
With the long term aim of cutting overall emissions by 60% by 2050, and by 80% by 2100, the intention of the 2006 changes was to cut energy use in new housing by 20% compared to a similar building constructed to the 2002 standards. The changes were the first to the regulations brought about by the desire to reduce emissions, though some have raised doubts about whether they will actually achieve the 20% cut (see criticisms section).
In the 2006 regulations, the u-value was replaced as the primary measure of energy efficiency by the Dwelling Carbon Dioxide Emission Rate (DER), [ [http://www.sbsa.gov.uk/current_standards/SummaryofSection6compliancemethodsandcarbondioxideratings.htm Dwelling Carbon Dioxide Emission Rate] ] an estimate of carbon dioxide emissions per m² of floor area. This is calculated using the Government's Standard Assessment Procedure for Energy Rating of Dwellings (SAP 2005). [ [http://projects.bre.co.uk/sap2005/ Standard Assessment Procedure for Energy Rating of Dwellings 2005] , "
Building Research Establishment"]
In addition to the levels of insulation provide by the structure of the building, the DER also takes into account the airtightness of the building, the efficiency of space and water heating, the efficiency of lighting, and any savings from
solar poweror other energy generation technologies employed, and other factors. For the first time, it also became compulsory to upgrade the energy efficiency in existing houses when extensions or certain other works are carried out.
Some organisations have raised doubts over the claim that the changes will result in a 20% saving. Issues cited have included alleged problems with the calculation methods, the limitations of the modelling software, and the specification of the reference building used in the model. [http://www.aecb.net/PDFs/NewHomesCO2Savings25May06.pdf] For example, a 2005 study sponsored by the Pilkington Energy Efficiency Trust [ [http://www.pilkington.com/europe/uk+and+ireland/english/building+products/pilkington4architects/peet.htm Pilkington Energy Efficiency Trust] ] indicated that the savings would only be in the region of 9%. [ [http://www.nher.co.uk/pages/insight/The%20Impact%20of%20proposed%20changes%20to%20Part%20L1A.pdf Microsoft Word - Report A.doc ] ]
There are also concerns about enforcement, with a
Building Research Establishmentstudy in 2004 indicating that 60% of new homes do not conform to existing regulations. [ [http://www.eeph.org.uk/uploads/documents/partnership/Building%20Regs%20Compliance%20Report%20Oct%2004.pdf Assessment of Energy Efficiency impact of Building Regulations Compliance] , prepared by the " Building Research Establishment" for the Energy Saving Trust/ Energy Efficiency Partnership for Homes, published 2004-11-10, accessed 2007-08-09] A 2006 survey for the Energy Saving Trustrevealed that Building Control Officers considered energy efficiency 'a low priority' and that few would take any action over failure to comply with the Building Regulations because the matter 'seemed trivial'. [ [http://www.energysavingtrust.org.uk/uploads/documents/partnership/Building%20Regs%20Part%20L1%202002%20Compliance%20Research%20May%2006.pdf Part L1 - an investigation into the reasons for poor compliance] , " Energy Saving Trust", published 2006-05-03, accessed 2007-05-18] [ [http://www.ukace.org/pubs/articles/eibi2006-03.pdf Time to put a stop to the disdain for regulations] , "Association for the Conservation of Energy", published March 2006, accessed 2007-08-09]
Despite the tightening of the requirements and previous loopholes, the regulations have been criticised by some for not going further. Criticisms include the exclusion of domestic appliances from the calculations, not requiring provision to be made for retrofitting of solar or other technologies, lack of remedial requirements if airtightness tests are failed, and for not requiring greater insulation standards.
A more fundamental criticism by some is that even if the expected 20% cut is achieved, this falls far short of achieving the long term goal of a 60% cut in carbon dioxide emissions by 2050. The London Sustainable Development Commission, [ [http://www.london.gov.uk/mayor/sustainable-development/sustainable_development_commission.jsp London Sustainable Development Commission] ] for example, has calculated that to meet the 60% target, all new developments would have to be constructed to be carbon-neutral with immediate effect (using
zero energy buildingtechniques), in addition to cutting energy used in existing housing by 40%.
A further issue is the omission of the impact of domestic sector
air conditioningin the projections. Air conditioning is beginning to gain acceptance in the domestic sector, driven in part by cheap self-install systems from the Pacific Rim, but with the established brands now also offering specifically targeted professionally installed ranges. Demand for cooling systems is rising mainly due to increased awareness, since air conditioning is standard on almost all new cars sold in the UK and also in the commercial sector, but also because of tight housing densities and long working hours, leading to problems with heat at night. The latter problem is compounded by the 'energy efficient' new build features such as tight insulation and small windows.
In December 2006 the government announced their 'ambition' that all new housing should be build to zero-carbon standards from 2016, [ [http://www.hm-treasury.gov.uk/pre_budget_report/prebud_pbr06/report/prebud_pbr06_repindex.cfm Pre-Budget Report 2006] ,
HM Treasury, published 2006-1206, accessed 2008-06-02] i.e. that the carbon emitted during a typical year should be balanced by renewable energygeneration. Despite being the first country in the world to adopt such a policy [ [http://www.independent.co.uk/environment/climate-change/britains-year-zero-uk-to-leap-from-laggard-to-leader-on-carbon-dioxide-emissions-786534.html UK to leap from 'laggard to leader' on carbon dioxide emissions] , The Independent, published 2008-02-24, accessed 2008-06-02] the initiative was generally welcomed by the industry in principle, [ [http://www.hbf.co.uk/Press-Releases-Statements-Archive-7ca9f9e HBF welcomes Government’s environmental vision on housing] , Home Builder's Federation, December 2006 press releases, published 2006-12-15, accessed 2008-06-02] despite some subsequent concern over the practicalities. [ [http://www.architectsjournal.co.uk/news/dailynews/2008/03/governments_2016_zerocarbon_homes_target_too_unrealistic.html Government's 2016 zero-carbon homes target 'too unrealistic'] , Architects Journal, published 2008-03-06, accessed 2008-06-02] [ [http://www.mikebriggs.org/html/zero_carbon.html Zero-carbon construction] , M Briggs, [http://rsh.sagepub.com/cgi/reprint/128/1/16 RSPH] , published January 2008, accessed 2008-06-02]
In 2004 the Government indicated that the next revision to the energy performance standards of the Building Regulations would be in 2010. [ [http://www.communities.gov.uk/publications/planningandbuilding/partl Proposals for amending Part L of the Building Regulations and Implementing the Energy Performance of Buildings Directive] , Department for Communities and Local Government, published 2004-07-23, accessed 2008-06-02] In the consultation document "Building a Greener Future: Towards Zero Carbon Development" it is proposed that the 2010 revision should require a further 25% improvement in the energy/carbon performance, in line with the 2004 proposals. [http://www.communities.gov.uk/archived/publications/planningandbuilding/buildinggreener Building a Greener Future: Towards Zero Carbon Development - Consultation] ,
Department for Communities and Local Government, published 2006-12-13, accessed 2008-06-01] It is further envisaged that there would be a 44% improvement in 2013, compared to 2006 levels. This would then be followed by the adoption of a zero carbon requirement in 2016, applied to all home energy use including appliances. These steps in performance would align the energy efficiency requirement of the Building Regulations with those of Levels 3, 4 and 6 of the Code for Sustainable Homesin 2010, 2013 and 2016 respectively [ [http://www.communities.gov.uk/documents/planningandbuilding/pdf/Energyefficiencyrequirements.pdf Building Regulations Energy efficiency requirements for new dwellings] , page 5, Department for Communities and Local Government, published July 2007, accessed 2008-06-02]
Home energy labelling
Originally, from June 2007, all homes (and other buildings) in the UK would have to undergo Energy Performance Certification before they are sold or let, [ [http://www.odpm.gov.uk/index.asp?id=1002882&PressNoticeID=2174 Communities and Local Government ] ] in order to meet the requirements of the European Energy Performance of Buildings Directive (Directive 2002/91/EC). [ [http://europa.eu/eur-lex/pri/en/oj/dat/2003/l_001/l_00120030104en00650071.pdf European Energy Performance of Buildings Directive (Directive 2002/91/EC)] , Official Journal of the European Communities, published 02-12-16, accessed 2008-06-02] (This has now been put back to August 2007, and will operate on a phased introduction basis, starting with large 4 bedroom homes). This will provide the owner or landlord with an 'energy label' so that they can demonstrate the energy efficiency of the property, and is also to be included in the new
Home Information Packs.
It is hoped that energy labelling will raise awareness of energy efficiency, and encourage upgrading to make properties more marketable. Incentives may be available for carrying out energy conservation measures. [ [http://www.gnn.gov.uk/content/detail.asp?ReleaseID=228873&NewsAreaID=2 Cooper calls for incentives to improve home energy ratings] , Government News Network, published 06-09-21, accessed 2008-06-02]
For new building, SAP 2005 calculations are to form the basis for the certification, while the
National Home Energy Ratingscheme (NHER) will be used to assess existing properties. It is estimated that only 10% of the nation's housing will score above 60 on the scale, although most will score above 40. [" New Scientist, November 2005"]
Other rating schemes
Another rating scheme of note is the Government sponsored
EcoHomesrating, mostly used in public sector housing, and only applicable to new properties or major refurbishments. This actually measures a range of sustainability issues, of which energy efficiency is only one. EcoHomes is to be replaced by the Government's Code for Sustainable Homesin 2007.
Energy Saving Trustset requirements for 'good practice' and 'advanced practice' for achieving lower energy buildings, [ [http://www.est.org.uk/housingbuildings/professionals/standards/goodandadvanced/ About Good and Advanced practice ] ] while the Association for Environment Conscious Building's "CarbonLite" programme specifies Silver and Gold standards, the latter approaching a zero energy building.
low carbon buildings programmewas launched in 2006 to replace the earlier "Clear Skies" and "Solar PV" programmes. It offers grants towards the costs of solar thermal heating, small wind turbine, micro hydro, ground source heat pump, and biomass installations. As of January 2007 funding for grants is proving insufficient to meet demand. [ [http://www.r-p-a.org.uk/article_default_view.fcm?articleid=2322&subsite=1 Renewable Energy Association - News Article ] ]
A similar scheme, the
Scottish Community and Household Renewables Initiativeoperates in Scotland, which also offers grants towards the cost of air source heat pumps.
Home Energy Conservation Act 1995, local authorities are required to consider measures to improve the energy efficiency of all residential accommodation in their areas. However they are not required to implement any measures, and only a minority of local authorities have done anything to inform or help households other than those in social housing and the fuel poor. It was expected that the Act would result in a 30% cut in energy usage between 1996 and 2010. An overall cumulative improvement of 14.7% was reported to DEFRA for the year ending March 2004, but a large part of this would have happened without HECA. [ [http://www.communities.gov.uk/index.asp?id=1155821] ]
In the SouthFact|date=November 2007 most local authority housing was sold off in the 1980s-90s under RTB (
Right to buy scheme), so the remaining stock is small. Much social housing has also been transferred to housing associations.
Demonstration and pioneering projects
One of the most important energy efficiency demonstration projects was the 1986
Energy Worldexhibition in Milton Keynes, which attracted international interest. Fifty-one houses were built, designed to be at least 30% more efficient than the Building Regulations then in force. This was calculated using the Milton Keynes Energy Cost Index (MKECI), a test-bed for the subsequent SAP rating system and the National Home Energy Ratingscheme.
The Beddington Zero Energy Development (
BedZED), a non-traditional housing scheme of 82 dwellings near Beddington, London included zero energy usage as one of its key features. The project was completed in 2002 and is the UK's largest eco-development. The only energy used is generated from renewables on site. Due to their superinsulation, the properties use 73% less energy for space heating compared to those built to the 2002 Building Regulations, while the reduction for water heating is 44%.Fact|date=February 2007 The Green Buildingin ManchesterCity Centre and has been built to high energy efficiency standards and won a 2006 Civic Trust Award for its sustainable design. [ [http://www.civictrust.org.uk/cta2006/sponsorpages/sponfgreenbuild.htm Civic Trust Award] ] The cylindricalshape of the ten storey tower provides the smallest surface area related to the volume, ensuring less energy is lost through thermal dissipation. Other technologies including solar water heating, a wind turbineand triple glazing.
South Yorkshire Energy Centreat Heeley City Farmin Sheffieldis an example of refurbishing an existing property to show the options available. [ [http://www.syec.co.uk South Yorkshire Energy Centre] ]
The EcoHouse in Leicester [ [http://www.gwll.org.uk/ecohouse/] ] incorporates products and materials selected for their green credentials, and operates as an advice centre with videos on products and suppliers, and refurbished computers for sale.
International comparisons of particular note include:
*The 1977 Danish "BR77" standard (the first to set demanding energy efficiency requirements).
*The SBN-80 (Svensk Bygg Norm) 1980 Swedish Building Standards, which in 1983 was in advance of the UK 2002 standards. [ [http://www.arkitektur.lth.se/?document=EBD/Utbil/TNA265/TNA265-F2_nul%C3%A4ge%20o%20historisk%20%C3%A5terblick.pdf Arkitektur och byggd miljö: Institutionen för arkitektur och byggd miljö ] ]
*The voluntary Canadian
R-2000standard, to which around 14,000 houses had been built in the 10 years to 1992. [ [http://www.bpa.gov/Energy/n/reports/Results_Center/pdf/26.pdf R-2000 Energy Efficiency Home Program] , Energy, Mines and Resources, Canada, published 1992, accessed 2008-06-02]
Since then many more have been built in Canada, in
Japan, and in various other countries including a number in the UK. Currently energy savings of 30% to 40% are typically achieved in Canada. [ [http://r2000.chba.ca/Why_buy_an_R2000_home/energy_efficiency.php Welcome to R-2000 ] ]
*The voluntary German
Passivhausstandard. Properties built to the standards use approximately 85% less energy and produce 95% less carbon dioxide compared to properties built to the UK's 2002 standards. Over 6,000 such houses have been built across several European countries. [ [http://www.passivhaustagung.de/elfte/english/01_start_home.html www.passivhaustagung.de ] ]
*The voluntary Swiss
Minergiestandard which requires that general energy consumption must not to be higher than 75 % of that of average buildings and that fossil-fuel consumption mustnot to be higher than 50 % of the consumption of such buildings, and the Minergie-P standard, requiring virtually zero energy consumption.
In 2005 the Select Committee on Environmental Audit expressed their concern that there was a lack of significant funding for research and development of sustainable construction methods, [ [http://www.publications.parliament.uk/pa/cm200405/cmselect/cmenvaud/135/13507.htm#n118 House of Commons - Environmental Audit - First Report ] ] with funding for the
Building Research Establishmenthaving been 'drastically' cut in the previous 4 years. As a result, many of the sustainable building materials used in the UK are imported from Germany, Switzerlandand Austria- some of the countries that have been prominent in research.
Existing housing stock
Even if all new housing does become 'zero carbon' by 2016, the energy efficiency of the remainder of the housing stock would need to be addressed.
The 2006 "Review of the Sustainability of Existing Buildings" revealed that 6.1 million homes lacked an adequate thickness of loft insulation, 8.5 million homes had uninsulated cavity walls, and that there is a potential to insulate 7.5 million homes that have solid external walls. These three measures alone have the potential to save 8.5 million tonnes of carbon emissions each year. Despite this, 95% of home owners think that that the heating of their own home is currently effective. [ [http://www.communities.gov.uk/index.asp?id=1504372] ]
Historic building regulations energy efficiency requirements
The u-value limits introduced in 1965 were: Solar Energy Applications in Houses, F Jäger, ISBN 0-08-027573-7, page 54]
*1.7 for walls
*1.4 for roofs
1973 oil crisis, these were tightened in 1976 to: The Building Regulations 1976, ISBN 0-11-061676-6, page 96 ]
*1.0 for exposed walls, floors and non-solid ground and exposed floors
*1.7 for semi-exposed walls
*1.8 average for walls and windows combined
*0.6 for roofs
1985 saw the second tightening of these limits, to:
*0.6 for exposed walls, floors and ground floors
*1.0 for semi-exposed walls
*0.35 for roofs
These limits were reduced again in 1990:
*0.45 for exposed walls, floors and ground floors
*0.6 for semi-exposed walls
*0.25 for roofs
*plus a requirement that the area of windows should not be more than 15% of the floor area.Like the 2006 changes, it was predicted that the introduction of these limits would result in a 20% reduction in energy use for heating. A survey by
Liverpool John Moores Universitypredicted that the actual figure would be 6% "(Johnson, JA “Building Regulations Research Project”)".
In the 1995 Building Regulations, insulation standards were cut to the following U-values:
*0.45 for exposed walls, floors and ground floors
*0.6 for semi-exposed walls and floors
*0.25 for roofs
*the limit on window area was raised to 22.5%
The 2002 regulations reduced the U-values, and made additional elements of the building fabric subject to control. Although there was in practice considerable flexibility and the ability to 'trade off' reductions in one are for increases in another, the 'target' limits became:
*0.35 for walls
*0.25 for floors
*0.20 or 0.25 for pitched roofs (depending on the construction)
*0.16 for flat roofs
*2.2 for metal framed doors and windows
*2.0 for other doors and windows
*the limit on window area was raised again to 25%
Similar limits were introduced into
Scotlandin 2002 & 2006, though with a lower limit of 0.3 or 0.27 for walls, and some other variations.
It was claimed by Government that these measures should cut the heating requirement by 25% [http://www.dti.gov.uk/energy/inform/save/save2002.pdf DTI: Energy efficiency in the UK 1990-2000, pdf file] compared to the 1995 Regulations. It was subsequently also claimed that they had achieved a 50% cut compared to the 1990 Regulations. [http://www.dti.gov.uk/files/file10719.pdf 2003 Energy White Paper] , page 34
While the u-value ceased being the sole consideration in 2006, u-value limits similar to those in the 2002 regulations still apply, but are no longer sufficient by themselves. The DER, and TER (Target Emission rate) calculated through either the Uk Government's Standard Assessment Procedure for Energy Rating of Dwellings (SAP rating), 2005 edition, or the newer SEBM* (*Small Energy Building Model)which is aimed at non-dwellings, became the only acceptable calculation methods. Several commercial energy modeling software packages have now also been verified as producing acceptable evidence by the BRE Global & UK Government. Calculations using previous versions of SAP had been an optional way of demonstrating compliance since 1991(?). They are now a statutory requirement (B. Reg.17C et al) for all building regultions applications, involving new dwelling/buildings and large extensions to existing non-domestic buildings.
* [http://www.epc-graph.com Free Online EPC Graph Creation Tool]
Energy use and conservation in the United Kingdom
Climate Change and Sustainable Energy Act 2006
Code for Sustainable Homes
Energy Saving Trust
* [http://projects.bre.co.uk/factfile/energyefficiency.html BRE: The historical role of energy efficiency in UK housing stock]
* [http://projects.bre.co.uk/factfile/BR457prtnew.pdf BRE: Domestic Energy Fact File]
* [http://www.leedsmet.ac.uk/as/cebe/projects/cobra04-1.pdf Energy Efficiency in Existing Buildings: The Role of Building Regulations]
* [http://www.buildingsplatform.org/cms/ Energy Performance of Buildings Directive Website]
DEFRA[http://www.defra.gov.uk/environment/climatechange/uk/energy/research/ Domestic energy research]
* [http://www.communities.gov.uk/index.asp?id=1143908 Planning Policy Statement 22 (PPS22) on renewable energy]
University of Oxford[http://www.eci.ox.ac.uk/lowercf/40house.html Oxford University 40% House initiative]
* [http://www.lmu.ac.uk/as/cebe/projects/york/york_final.pdf Leeds Metropolitan University: York Energy Demonstration Project (1998)]
* [http://www.nef.org.uk/energyadvice/erhome.htm The National Energy Foundation]
* [http://www.cat.org.uk Centre for Alternative Technology]
* [http://www.aecb.net the Association for Environment Conscious Building]
* [http://www.shadlock.co.uk/ Practical Home Energy Conservation]
In the media
*Jan 2007, HBF: [http://www.hbf.co.uk/index.php?id=1577&tx_ttnews=10123 Landmark summit to determine how to deliver Government’s environmental vision]
*Dec 2006, SP [http://www.stirlingpartners.com/index/newsstory/00046/ No stamp duty on zero carbon homes]
*Sep 2006, New Builder: [http://www.newbuilder.co.uk/news/newsFullStory.asp?ID=1580 Housing Minister: Homes should exceed Scandinavian specifications in 10 years]
BBC: [http://news.bbc.co.uk/2/hi/science/nature/5194986.stm eco-targets at risk unless households cut resource use]
The Guardian: [http://www.guardian.co.uk/climatechange/story/0,12374,1530811,00.html Energy-saving targets scrapped for housing]
BBC: [http://news.bbc.co.uk/1/low/sci/tech/4373135.stm Call to demolish polluting homes]
Wikimedia Foundation. 2010.