The Construction Centre
Magnifying Glass

Code for Sustainable Homes

The Code for Sustainable Homes

Explore our comprehensive guide to The Code for Sustainable Homes by selecting an item below...

Web Guide to The Code For Sustainable Homes

The following guide to the Code for Sustainable Homes has been created by The Construction Centre as a useful reference tool to help users familiarise themselves with the contents of the Code and give an overview of the design considerations that must be taken on board in order to build a Code compliant dwelling. The Guide provides information on compliance with and the necessary assessment criteria of all categories within the Code. Information regarding Code related products and professional services are provided for easy sourcing and to enable a route to compliance. Further explanatory text providing background information on elements covered by the Code is also available. The guide created by The Construction Centre.co.uk is for research and information only and should not be relied upon for code compliance. The Guide is based upon the Communities and Local Government publications;

Note: In November 2010 the Code for Sustainable Homes was updated to help simplify key areas and to bring it line with recent changes to building regulations. The new technical guidance and summary of changes to the Code for Sustainable Homes documentation can be found below.

These documents form the Code for Sustainable Homes and it is recommended that these should be used for technical reference or an Accredited Code Assessor should be contacted for advice.

The links below open the 2008 issue of The Code for Sustainable Homes:

Government Targets

The first legally binding carbon budgets were announced by the Government in the 2009 budget. The carbon budgets represent stepped legally binding limits on greenhouse gas production within the UK. Carbon budgets were introduced following the Climate Change Act that became law in November 2008, which set new legislation to cut UK greenhouse gas emissions by 60% by 2050.

In addition, the Kyoto Protocol requires a 20% reduction in carbon dioxide by 2010. The Government's study 'United Kingdom Climate Projection' illustrates that the effects of climate change within the UK are likely to involve warmer winters, with increased rainfall contributing to flooding and sea levels rising, accompanied by hotter summers with more drought and intense heat waves.

In order to combat climate change the Government is implementing a range of policies to reduce greenhouse emissions across many different sectors. The built domestic environment represents one of the largest contributors to green house gases, especially carbon dioxide.

The Code for Sustainable Homes (CSH) has been introduced to support the government's target that all new homes will be zero carbon from 2016 and to improve the overall sustainable and environmental standards of newly constructed homes throughout the nation.

The definition of the term zero carbon is currently being revised by the Government and will be updated within the Code as soon as the announcement is made. Our interpretation of a zero carbon home is defined as a building where net carbon dioxide emissions from all energy used in the dwelling are zero or better. This takes into account all energy used for heating (water and space heating), lighting, ventilation, cooling, cooking and electrical appliances. By improving environmental and sustainable building practises, the code enables home buyers to make an informed decision regarding the sustainability credentials of their new property and the associated likely running costs.

Introduction to the Code for Sustainable Homes (CSH)

The Code for Sustainable Homes replaces the Ecohomes Scheme (within England) developed by Building Research Establishment (BRE). It was officially launched on 13th December 2006 after introduction as a voluntary standard in England during April 2007.

Consequently all new social housing projects are required to meet level 3 code requirements, however the code does not apply within Scotland and level 3 rated homes are required for public sector buildings within Northern Ireland. The Welsh Assembly have adopted the code for all their new and promoted social housing projects. The government has specified that the London Olympic Village, for the 2012 Olympics, should be built to Code level 4 requirements and that any Eco Towns built should achieve a Code level 5 or 6.

With the latest changes to Building Regulations now in force and the updates to the Code in place, many local authorities will require Code Level 4 on new developments from April 2011.

About the Code for Sustainable Homes

The code uses nine different design categories to rate the home as a 'whole' unit by reviewing its sustainability performance within each of the key design categories. Ratings are given to each category using a one to six star scale system.

Since 1st May 2008 it has been a mandatory requirement to rate all new homes against the code. This however does not mean that new homes have to be built to the code, instead they have to be rated against the code and a certificate made available within the Home Information Pack (HIP) as evidence to potential buyers of the homes sustainability credentials.

Two options are open to developers:

  • Choose to build a code compliant home from the outset of the project and have the home assessed against the code to achieve a star rating. A certificate will then be issued stating the star rating obtained. The certificate should then be included within the HIP.
  • Choose to build a home which complies with current building regulations and download a free nil-rated certificate to provide to the home buyer. If this option is taken, a paid assessment is not required; however the sustainability credentials of the home will not be clear to potential buyers. The nil-rated certificate should then be included within the HIP.

Recent History

The May 2009 version only applies to homes registered before this date.

Documentation

Note: In November 2010 the Code for Sustainable Homes was updated to help simplify key areas and to bring it line with recent changes to building regulations. The new technical guidance and summary of changes to the Code for Sustainable Homes documentation can be found below.

These documents form the Code for Sustainable Homes and it is recommended that these should be used for technical reference or an Accredited Code Assessor should be contacted for advice.

The links below open the 2008 issue of The Code for Sustainable Homes:

Related Core Documents

Following the introduction of the Code, a number of additional publications have been released to aid its integration to the development of sustainable building practises and specifications to help meet the Code’s requirements by offering practical solutions. Selected Communities and Local Government publications:

Since the introduction of the Code, the Energy Saving Trust has published a series of guides identifying the considerations and structural requirements, which can be used to build Code compliant dwellings. Three guides are available, each aimed at specific Code levels, detailing how they may be achieved;

Other available publications that provide valuable information; Cracking the Code – How to achieve Code level 3 and above (Sustainable Homes)(pdf)

Latest Updates

A consultation was undertaken on Part F (Means of ventilation) and Part L (Conservation of fuel and power) building regulations between June and September 2009. Revised building regulations for part F and L were introduced in October 2010 with revisions to Part J also. Both Part F and L building regulations under pin the concept of the Code as they inadvertently govern levels of energy efficiency and carbon dioxide emissions (to which ventilation plays an import role) which are acceptable for a dwelling to be granted planning permission.

Previously a Code level 3 rated dwelling had to perform 25% above the 2006 Part L building regulations, with other Code levels also performing above Part L building regulations on a stepped scale. Now the revised building regulations have become more stringent, driving higher code level homes to be built out of necessity to satisfy legal building regulation requirements.

The consultation closed on 24th March 2010 for addressing what changes needed to be made to the Code in response to the revision of Parts F, J and L building regulations. From November 2010 Code levels 1-3 now show a 0% improvement over Part L building regulations 2010. Higher Code level targets have altered to align with this:

  • Level 4 showing a 25% improvement
  • Level 5 showing a 100% improvement
  • Level 6 Net Zero C02 Emissions

The consultation paper 'Sustainable New Homes: The Road to Zero Carbon' (pdf) deals with areas of the Code which are being considered for revision.

Code Level Table

Sustainable New Homes - The road to carbon zero (pg.13) showing scheduled improvements over Part L building regulations.

Overview of the Assessment Procedure

The code uses nine different design categories to rate the home as a 'whole' unit by reviewing its sustainability performance within each of the key design categories. Ratings are given to each category using a one to six star scale system, with one star indicating 'entry level' requirements (above the level of the Building Regulations) and six stars indicating the 'highest level' reflecting ideal sustainability credentials. A six star rating (level 6) indicates the home is carbon zero.

The nine design categories used for the code assessment:

  • Energy Efficiency and CO2 Emissions
  • Water
  • Materials
  • Surface Run-off
  • Waste
  • Pollution
  • Health and Well-being
  • Management
  • Ecology

Minimum standards are set for six categories and with each ascending level of the code gained, the minimum standards increase in the energy efficiency and water efficiency design categories. This illustrates their importance in creating a sustainable home and must be achieved at whatever Code Level rating is desired:

  • Energy Efficiency and CO2 emissions: Dwelling Emission Rate (DER), Fabric Energy Efficiency (FEE)
  • Water Efficiency: Indoor Water Use
  • Materials: Environmental Impact of materials
  • Surface water run-off: Management of Surface Water Run-off from Developments
  • Waste: Storage of non-recyclable waste and recyclable household waste
  • Health and Well Being: Lifetime Homes

Note: Environmental impact of materials, management of surface water run-off and storage of non-recyclable and recyclable goods do not have credits awarded but are an entry level requirement. DER and indoor water use do hold credits and will have increasing mandatory requirements. The FEE must gain 7 credits or more in Ene2 for Level 5 and for Level 6 Lifetimes Homes must have 3 credits in Hea4.

A set number of credits are allocated to each of the nine design categories with 100 credits available in total for the home as a whole. A developer can choose which areas in which to gain credits in order to achieve a higher sustainability rating, as long as compulsory minimum standards have been met within specified design categories. The table below shows the minimum point scores for each Code level.

The Code for Sustainable Homes - Purpose (table 1.6, pg. 17)

The Code for Sustainable Homes - Purpose (table 1.6, pg. 17)

The credits within each design category are weighted out of 100% for the whole home based on their importance to the overall sustainability of the home. The sustainability star rating for each design category of the home is calculated by taking into account the number of credits earned in each design category against their weighted worth. Weightings apply to the category not individual credits. It is also worth bearing in mind that achieving high performance in one area could result in a lower level of performance in another.

The Code for Sustainable Homes - Purpose (table 1.4, pg. 13)

The Code for Sustainable Homes - Purpose (table 1.4, pg. 13)

Assessment

The assessment comprises a two stage process:

  • Assessors conduct an Initial Design Stage Assessment to check the designed elements and specifications of the dwelling are likely to fulfil requirements for the Code level desired. If approved, a Code Assessor will issue an Interim Code Certificate for the dwelling.
  • Following construction, a Post Completion Check is undertaken by the Code Assessor to verify that the elements and specifications of the home have actually been built as designed. To enable this verification process, items such as purchase invoices, manufacturer product specifications and photographic evidence will be required. It may also be necessary for the Code Assessor to undertake site visits. Once the Post Completion Check has been carried out the Code Assessor will issue a Final Code Certificate giving the relevant Code rating accompanied by the corresponding star rating.

Assessment Bodies

Currently only two professional assessment bodies (Robust Details Ltd and Stroma Ltd) are licensed to provide Code Services. These assessment bodies also hold a list of licensed and accredited assessors with the ability to assess homes against the Code and enable certification.

The assessment bodies are responsible for upholding the Code's practice and a number of other functions including;

BRE Global Ltd: Operate the BREEAM (BRE Environmental Assessment Method) which formed the basis of the Ecohomes Scheme which has now been replaced by the Code for Sustainable Homes (CSH). .Assessment and accreditation according to the Code for Sustainable Homes can be undertaken by any BREEAM Assessor registered with them. Variations of BREEAM can be used to assess the environmental performance of existing buildings undergoing major refurbishments such as houses, offices, factories, leisure centres, prisons, retail facilities, hospitals and schools.

Additonal Information

BREEAM:

Find a licensed BREEAM Code Assessor

Want to become a BREEAM Registered Code Assessor

Stroma Ltd:

Stroma Ltd: Provide home assessments to satisfy the Code for Sustainable Homes. An advisory service is offered for private and social housing projects along with the option of a design stage service to ensure that target Code levels can be met cost effectively and efficiently.

Find a licensed Stroma Assessor

Become a Stroma Registered Assessor

Many private assessment companies exist who employ assessors registered by either BRE Global Ltd or Stroma Ltd.

Assessment Professionals: Code Assessors

The Code