Hoare Lea’s study into the changes in the software used to calculate compliance with Part L

The deadline for responses to the proposed 2010 revision of Part L is fast approaching and if you haven’t read the 800 pages already, you probably won’t, writes Steve Wisby. Although the headlines are that there is some simplification and an attempt to help building control enforce the regulations, the complexity of the calculations makes it difficult to comment by inspecting the document alone.

Hoare Lea’s study modelled two 2006-compliant buildings using the trial software. There were a few surprises, not least its apparent favouring of fan-coil systems over ventilation with passive cooling. There also appears to be some obvious coding errors. Of perhaps greater significance was that, on the buildings modelled, it seemed compliance could only be achieved with renewable energy such as wind or solar, indicating that improvements in energy efficiency are reaching their cost-effective limit.