- SAP Rating UK – House Heat Loss Regulations UK – EPC – Building Regulations UK -
	DSJ Planning & Design			SAP Energy Ratings TER/DER
Home Services Guidance Notes Contact Us	Welcome To comply with the current Building Regulations all new dwellings are required to have a SAP (TER/DER) calculation which should be carried out before construction commences. On completion the SAP is re-calculated using the pressure test results (if applicable) and the details of the actual boiler used. This then provides the information which is included in the EPC (Energy Performance Certificate). SAP (Standard Assessment Procedure) ratings were first introduced in 1995 and are the Government’s recommended system for the energy rating of new dwellings. Since it’s commencement the system has been upgraded twice to reduce the carbon footprint of new dwellings: SAP 2001 was introduced in December 2001 when the system had a scale from 1 to 120 and the rating was solely based on the annual energy costs for space and water heating where 1 was very poor and 120 was excellent. This system is still used to provide calculations for dwellings that have been recently completed but had their Building Regulations approved prior to April 2006. If an EPC is required on one of these dwellings the calculations have to be converted to the SAP 2005 calculation. SAP 2005 was introduced in April 2006 with a new scale from 1 to 100 where again 1 is very poor and 100 is virtually self sufficient. This calculation introduced the TER/DER values where the TER is the Target Carbon Dioxide Emission Rate, which is calculated by the SAP programme based on a notional dwelling of the same size and configuration but calculated on the 2001 system with a 20% improvement. The DER is the Dwelling Carbon Emission Rate calculated on the proposed design (which should be based on the current Part L of the Building Regulations), and this figure must equal or preferably better the TER figure. The only exception to the above is where dwellings are created by the conversion of an existing building. The Scottish version is similar but there are some slight variations to the programme and to the values used in the calculation. In all cases (even for extensions) most Building Controls require the calculations to be submitted with the Building Regulation application. Constructing a dwelling under a Building Notice is extremely risky as a SAP (TER/DER) will still be required before Building Control can provide a completion certificate and if the dwelling fails the calculations remedial works could be extremely expensive. For new dwellings the standard U-values for the thermal elements (as detailed later) are only a guide because there are so many other factors that affect the TER/DER figures. In most cases these U-values will have to be bettered (sometimes considerably) in order for the dwelling to achieve a TER/DER pass. The following is a list of items which are now included in the SAP calculations and have the most effect on the TER/DER ratings: Orientation of the dwelling. Area of glazing – solar gain. Ventilation. Thermal Bridging and Air Leakage – Pressure Test. Energy Efficient Lighting. Use of green energy (geothermal and solar). Heating Controls and Secondary Heating (wood burning stoves). The current U-values are as follows: New Dwellings Conversions Walls 0.30W/m2K 0.35W/m2K Ground Floors 0.22W/m2K 0.25W/m2K Flat Ceilings 0.16W/m2K 0.16W/m2K Sloping Ceilings 0.20W/m2K 0.20W/m2K Flat Roofs 0.20W/m2K 0.25W/m2K Glazing 1.80W/m2K 1.80W/m2K The highlighted figures show the elements that have changed in the 2005 regulations. Typical SAP Values An existing average dwelling would most probably only achieve a SAP rating of about 45 whereas a new dwelling built to comply with the current Part L of the Building Regulations should achieve a SAP rating of 80 (depending on the type of heating fuel used).
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