Assume the worst acceptable efficiency permitted by the relevant Building Regulation or, the efficiency that would be required to ensure the Buildings Emission Rate (BER) is the same as or better than the Target rate (TER) so that it is compliant with Part L2 of the Building Regulations.
Note: Low or Zero Carbon (LZCs) technologies may have been specified to help a building achieve its TER; replacing the LZCs with a gas boiler results in the BER failing to achieve or better the TER and as such, the building is theoretically not compliant with Building Regulations. Under these circumstances, it is not considered robust for BREEAM compliance to account for the carbon dioxide emissions savings delivered by the specified LZCs in bringing the building’s BER up to the TER. Thus, where the BER is worse than the TER (for the purpose of this analysis) the percentage reduction in regulated CO2 emissions as a result of specifying an LZC technology should only account for CO2 savings made on the TER and not the BER.
