New SAP methodology will make zero carbon harder to reach, Dyfrig Hughes, principal consultant of NHER, has warned. Speaking at Housebuilder’s Zero carbon, Part F and Part L conference last month, Hughes said that the 2009 standard assessment procedure (SAP) would affect the dwelling emission rate (DER) of a new home – the estimated carbon dioxide emission rate per annum from total energy use of heating, hot water and lighting – and the target emission rate (TER) – the maximum emission rate that Buildings Regulations permit. The DER and TER calculations are used in the energy section of the Code for Sustainable Homes (CSH). “Energy consumption for heating is likely to increase as the industry moves from SAP 2005 to SAP 2009,” Hughes explained. Other changes to SAP methodology include space cooling considerations and recognition of thermal mass. SAP methodology is now out for consultation, whilst the software should be released this month. <br>