ºÃÉ«ÏÈÉúTV

The new Part L currently out to consultation will radically alter the way that designers have to approach energy efficiency of buildings. Compliance will be judged on the carbon emissions from the whole building rather than by heat loss through individual elements, so it will not be possible to specify ‘Walls to be compliant with Part L’ for example. Never mind the 25% to 30% improvement over the existing Part L, it is the way that compliance will be judged that is the big change.

The roots of this change are the Energy Performance in ºÃÉ«ÏÈÉúTVs Directive (EPBD), which has to be implemented into UK law by January 2006, and the Energy White Paper (EWP) of February 2003. The EPBD is the driver for the changes in compliance methodologies requiring whole building methods that take account of a wide range of factors including solar gain and renewables. The EWP brought forward the revision of Part L from 2007 to 2005 and stated that a significant level of improvement would be needed.

The Office of the deputy Prime Minister (ODPM) is responsible for the ºÃÉ«ÏÈÉúTV Regulations and they recognised the magnitude of the task and the tightness of the politically set timetable. Industry was brought into the process to input into the development of the consultation draft as it was recognised that the consultation draft had to be realistic first time out. There was not time to engage in a ‘ping pong’ type game of proposal and counter proposal.

The draft is generally felt to be realistic but there are some significant problems that need urgent work. One is that neither the domestic nor non-domestic compliance methodologies have been finalised. In fact, the non-domestic has not even been chosen yet. It is hoped that the domestic methodology (SAP2005) will be virtually finalised by the end of this year.

For the non-domestic it will be a struggle to get finalisation by June next year when Part L will be finalised. Another major problem is that there is a huge range of performance of existing Part L compliant buildings when measured in terms of carbon. Will the 25% improvement be from the worst, the average or the best? In detached housing, similar sized dwellings which comply to Part L 2002 can vary by 150% in terms of carbon emissions. When we look at non-domestic buildings with the new methodology, a similar variation could emerge.

In summary, Part L presents a huge challenge for all parts of the industry. These are big changes in a very tight timescale. The Construction Products Association is working hard with members on it. Your own preparation also needs to start now.