Sunand Prasad on the new Code for Sustainable Buildings
The RIBA president on the demand for clarity on green issues
In early 2005 at the Urban Summit in Manchester the initial draft of a proposed Code for Sustainable Buildings was issued to general disappointment. The government rethought the subject and came out at the end of 2006 with the Code for Sustainable Homes, to a wide welcome from all parts of the industry. It is timely to return to the original project and examine what a Code for Sustainable Buildings (CSB) might look like, learning from the CSH. The UK Green Building Council has done this over the last six months consulting a wide cross-section of the industry. The most significant conclusions of the exercise are firstly that a CSB is needed, albeit in quite different form from the CSH; secondly, that it should be owned by government but be developed, managed and implemented by industry; thirdly, that it must cover refurbishment as well as new build; and fourthly, that it must have ‘through life’ application covering design, construction and management of buildings.
The single factor that distinguishes the CSH more than any other is the provision of a regulatory escalator, whereby we can set a goal of achieving zero carbon homes by a certain date with intermediate targets leading up to it. This brings potential clarity and certainty, though much work remains to be done as regards Code levels 5 and 6. The CSB will adopt this aspect of the CSH but rather than a multi-criterion checklist like the CSH it will be a framework whereby targets for outcomes are set but the method of reaching them is not prescribed. There is much detail to be worked out but I hope that the final code will make good the intention of setting absolute targets with real numbers (for example, energy use and CO2 emission per m², litres of water use per person per day etc) rather than a system of credits where the number of bicycle spaces can be weighed against energy performance.
That brings us to the key issue that has been discussed throughout the work on the CSB. What do you include in such a code? One school of thought desires an all-encompassing tool that will give an overall sustainability score including social and economic factors. At the other pole is the notion that carbon can be the sole measure for not only does it represent the biggest part of the problem facing us it can act as a precisely measurable ‘proxy’ for all the sustainability ‘goods’. So for example if you look at the energy use in water supply and set out to minimise it, you would have to adopt all the water conservation practices indicated by any other method. The working group has adopted a middle line, rejecting the use of carbon as the only or dominant measure, but also accepting that to be effective and accurate the code will for the time being stick to a small number of key sustainability factors: energy, carbon, water, waste and materials. It is the nature of codes that detail is everything. The strategy is proposed; the real work begins now.