What Are RdSAP and SAP?
SAP is the acronym for Standard Assessment Procedure and RdSAP is a cut-down version of the procedure specifically for the energy assessment of existing dwellings.
SAP (Standard Assessment Procedure)
This is a Government approved system for assessing the energy efficiency and environmental impact of a new-build dwelling. It has been devised for the government by a number of organisations under the umbrella of FAERO (Federation of Authorised Energy Rating organisations).
All new-build dwelling must be built to accord with the UK Building Regulations 2000 Parts L1A for new dwellings. This is the procedure which checks and controls this from architects plans.
RdSAP (Reduced Data Standard Assessment Procedure)
This is a sub-set of the SAP and is specifically for existing dwellings where SAP would not be appropriate because of the difficulty in assessing such things as U-Values of insulation etc. RdSAP is designed to comply with the UK Building Regulations 2000 Part L1B for existing dwellings.
RdSAP software is devised for use by qualified DEAs (Domestic Energy Assessors) to provide an EPC (Energy Performance Certificate). The certificate will provide the home owner with an accurate assessment of the energy efficiency of their home and its environmental impact. Both of these are assessed on a scale A to G as follows:
A – 93-100 Points
B – 81-92 Points
C – 66-80 Points
D – 51-65 Points
E – 36-50 Points
F – 21-35 Points
G – 1-20 Points
The average UK home scores around 41 points. Some of the factors which score highly on RdSAP are:
+47 Condensing gas boiler
+40 Condensing Oil boiler
+10 250mm Roof insulation
+10 Cavity Wall Insulation
+8 Hot water cylinder thermostat and 33mm insulation
+4 Double glazing
+1 Draught proofing
