I contributed THIS OPINION PIECE to the BregsForum last year concerning Part L compliance of the Building Regulations. In it I said:

“The only way numerically (currently) to assess conformance with Part L of the Building Regulations is via the Dwelling Energy Assessment Procedure (DEAP) software. It is this software that allows the user to input the following:

Property Details
Property Dimensions
Ventilation details (Chimneys, ventilation type, air tightness etc…)
Building elements (Construction types, u values areas etc…)
Water heating
Lighting
The software on completion can give conformity results on U-values, renewables, primary energy use and CO2 emissions. The conformity with the Building Regulations is given in a straightforward green check (tick) or red cross. “

According to a recent article in passive house+ magazine this advice has now been superseded. In the article Dr Brian Motherway, the CEO of Sustainable Energy Authority of Ireland (SEAI) states:

“SEAI does…