Green building regulations and standards

There have also been changes toPart G of the Building Regulations, which regulates water supply and efficiency. These changes came into effect April 2010 and sections G1 through G6 include the main differences from the standards introduced in 2000.

Changes include new requirements on water efficiency in dwellings in connection with Regulation 17K, which states that new dwellings must not exceed the minimum water efficiency requirement of using less than 125 litres per person per day. This opens the door to exploring alternative technologies like harvested rainwater and grey water recycling for toilet flushing.

The Code for Sustainable Homes is the Government’s national standard for new housing, even though it is optional. It became effective in England in April 2007 and a Code rating for new homes became mandatory in May 2008. It is not compulsory for every new home to be built to the Code, but each home must contain a rating against the Code.

It incorporates all key Government sustainability targets into one standard, measuring sustainability against categories such as energy and CO2 emissions, water, materials, surface water run-off, waste, pollution, management, ecology, and health and well being.

A home is given a sustainability rating that ranges from one to six stars, where Level One is a modest improvement on minimum regulatory standards and Level Six is a zero carbon home with an exemplary level of sustainability performance.

In November 2010, the Government made changes to the Code For Sustainable Homes to bring it into line with new regulations such as the Part L of the Building Regulations as well as to simplify the Code.

Assessments are carried out in two phases:
• An initial assessment and interim certification is carried out at the design stage. This is based on design drawings, specifications and commitments, which results in interim certificate of compliance
• A final assessment and certification is carried out after construction. Based on the design stage review, this includes a confirmation of compliance including site records and visual inspection.

Shortly after the introduction of the Code in 2007, developers of demonstration homes on the BRE Innovation Park were among the first to try building to the Code’s higher levels and a four-part Information Paper produced by BRE explains the lessons learnt.

The experience gained from the Innovation Park provided lessons in terms of building fabric, energy and ventilation, water economy and materials. The Information Papers provide some of these findings:
• Simple house designs are easier to make airtight, as are large panel construction systems with few joints
• Windows and doors must be specified and installed for air tightness, day lighting and solar gain as well as thermal performance and sustainability
• Achieving Levels Five and Six requires the use of ‘renewable’ energy, either generated communally, or through micro-generation at each house. A range of energy technologies was installed on houses at the Park
• Appropriate shading, thermal mass and ventilation can minimise overheating
• Water use can be reduced while minimising the effect on the end user by using aerated showers and taps to increase perceived flow rate without increasing water use
• Careful specification of white goods can save water and earn credits under the Code
• Water butts that collect water from the roof are an effective, but must be fitted with functioning overflows.

The BREEAM assessment process was created in 1990 with the first two versions covering offices and homes. Versions are updated regularly in accordance with Building Regulations and different building versions have been created to assess various building types. BRE lists 13 BREEAM schemes on its website, many of which have the option to assess new buildings as well as refurbishment and extension projects.

BREEAM looks at eight main areas of assessment: energy, transport, water, pollution, management, material and waste, land use and ecology, and health and well being.
Credits are awarded in each of the above areas according to performance. A set of environmental weightings then enables the credits to be added together to produce a single overall score. The building is then rated on a scale of: Pass, Good, Very Good, Excellent, or Outstanding.

This assessment process has two stages: design stage and post construction. BREEAM has trained assessors who assess the evidence against the credit criteria and report it to the BRE, who validate the assessment and issue the certificate.

These BREEAM ratings provide benefits for developers and clients, such as recognition for low environmental impact buildings and a way to reduce running costs later.

BREEAM building assessments are required by various regulatory and Government organisations. English Partnerships set a BREEAM Very Good rating for non-domestic buildings, the Office of Government Commerce requires an Excellent rating for all new buildings, and the Department for Children, Schools, and Families mandates that new build and refurbishment projects achieve a Very Good rating under BREEAM Schools.