SAP & Environmental Impact

All new build houses require an energy rating, called a SAP (Standard Assessment Procedure). This calculates a rating for the energy cost due to the built structure of the home and its heating system, internal lighting and any renewable technologies used within the home. It does not include energy used for cooking or appliances. The SAP rating is adjusted for floor area so that it is effectively independent of the size of the dwelling. The SAP rating provides the basis for Energy Performance Certificates (EPCs), which place the SAP rating with a number between 1 and 100 + on an A-G scale. With the higher the number the lower annual heating and lighting cost per square metre. With an A being the lowest band and G being the highest. A SAP rating has been required for all new houses as part of the building regulations since 1995.

The Environmental Impact Rating (EI) is based on the estimated annual CO2 emissions per square metre due to space heating, water heating, ventilation and internal lighting, minus any CO2 saved by any electricity generation. It is expressed on a scale of 1-100+, with the higher the number the better the standard and is also placed on a scale A — G, with band A having the lowest environmental impact and G the highest.

What does all this mean?

Building regulations require new dwellings to demonstrate compliance with Approved Document Part L1A of the Building Regulations (2006) in England and Wales. This is concerned with an estimated annual CO2 emission rate per dwelling, with the primary goal of reducing carbon dioxide emissions. The requirements that came into effect in 2006, with the aim to reduce emissions by 20% when compared to standards that were outlined by the previous building regulations in 2002. This means that a construction today must produce 20% less emissions than building regulations outlined in 2002 as a minimum. The reality is, that the building will have to perform far in excess of this figure, as the Code For Sustainable Homes requires the carbon emissions to be a further % less for each corresponding code level from 1 to 6, with code level 6 being a true zero carbon building. For example code level 2 requires for the carbon emissions to be a further 20% improvement over and above the first 20% on 2002 building regulations. Code level 3 requires a further 30% improvement etc.