BRE has released the updated version of its Part L calculation software, ending months of frustration for consultants.

It has been working on the Simplified Building Energy Model software, which calculates energy efficiency in non-dwellings, since January. Consultants rejected the first version, saying the tool gave results that contradicted Part L guidance.

Designers said the program's results were not consistent with what the government were telling them to do.

They found that the SBEM software produced results with lower carbon emissions when single glazing was used in a building, but Part L documentation states single glazing is not allowed.

As well as a new version of SBEM and the interface iSBEM, the package also includes an updated user guide and supporting databases.

Improvements in the new version of the software include:

  • A new treatment of thermal bridges at construction junctions
  • Simplified ways of entering data applicable to the whole building
  • A wider range of weather locations and modifications to some of the underlying databases.