Updated software was due to be released alongside the new Part L of the Building Regulations next month

The Communities department has delayed the release of the software for calculating energy performance certificates (EPCs) of buildings by six months.

An updated version of the software was due to be released to coincide with the new Part L of the Building Regulations which comes into force on 1 October.

However, in an email the Communities department said it was deferring the release until 27 March 2011 to give it more time to better understand any significant differences in the EPC ratings between the existing and new versions.

An EPC is required when a building is completed, let or sold and the Communities department says that because new buildings conforming to Part L 2010 will not be completed until some appreciable time after October 2010, very few people will be affected.

However, David McEwan, director of software simulation provider IES, says that it won’t be possible to perform 2010 energy performance certificate calculations until next year and the only way to get an idea before then is to use the 2006 method.

This will complicate the compliance process for designers as they will be forced to use two different versions of software and those using iSBEM will have to build models twice using two different versions of the software.

He added that feedback from customers is that clients are already asking to understand the difference between 2006 and 2010 Part L and EPC calculations.