The Code for Sustainable Homes (CSH) was launched in 2006 and it called for a change in the way we think about the design and construction of new homes . The CSH is based on a rating of 1 to 6, it is mandatory in England and Wales to have a CSH assessment, in England only an assessment must be carried out and no rating has to be achieved, but generally houses in England are being designed to CSH standards. In Wales it is mandatory to achieve a star rating of 3, which is not difficult at all, and need not be too costly. The CSH is a great way of bringing the knowledge of sustainable design to the construction industry, for self builders and also large companies alike, more importantly designers are incorporating the CSH into every design and evolving more into sustainable design so that it will be the normal thing.
You can find their website at http://greenhomecode.com