Design Fabric Energy Efficiency (DFEE) calculations andTarget Fabric Energy Efficiency (TFEE)  

DFEE and TFEE calculations are now required for new dwellings. The came into force on 6th April 2014.

Prior to 6th April 2014 DER/TER calculations were required, both DER/TER calcualtions and DFEE/TFEE calculations are now required.

So what does this mean ?

While there have been changes to  other requirements regarding DER/TER calculations, the introduction of DFEE/TFEE have had the biggest impact, mainly on the following areas of design:-

U-Values

Air Testing

Junctions

These new changes make it more important to have the design fully passing before work starts on site. For a detailed explanation visit out New Dwellings overview page.