This is the methodology used by the Government to assess and compare the energy and environmental performance of dwellings. Its purpose is to provide accurate and reliable assessments of dwelling energy performances that are needed to underpin energy and environmental policy initiatives.

SAP works by assessing how much energy a dwelling will consume, when delivering a defined level of comfort and service provision. The assessment is based on standardised assumptions for occupancy and behaviour. This enables a like-for-like comparison of dwelling performance. Related factors, such as fuel costs and emissions of carbon dioxide (CO2), can be determined from the assessment.

SAP quantifies a dwelling’s performance in terms of: energy use per unit floor area, a fuel-cost-based energy efficiency rating (the SAP Rating) and emissions of CO2 (the Environmental Impact Rating). These indicators of performance are based on estimates of annual energy consumption for the provision of space heating, domestic hot water, lighting and ventilation. Other SAP outputs include estimate of appliance energy use, the potential for overheating in summer and the resultant cooling load.

The Government’s commitment that ‘new homes should be net zero carbon from 2016’ represents a challenge in terms of accurately and robustly assessing the performance of potentially lower-energy dwellings, given that some aspects of the performance may be delivered through off-site allowable solutions.

A key aspect of SAP’s future development will be to accurately reflect carbon emissions reduction from both on-site and off-site performance measures. Working with stakeholders, DECC intends to review SAP to determine how it may be developed to deliver this policy initiative. Reduced Data SAP will also be reviewed to ensure it remains fit to deliver the policy initiatives that it underpins.

The underpinning information, product performance and other relevant data that the assessment tools rely upon, must be produced to a high level of accuracy and reliability.DECC will be asking stakeholders to contribute to the achievement of that aim.

What is the difference between a SAP calculation and an Energy Performance Certificate?

The SAP calculation is the method used for demonstrating compliance with the Building Regulations whereas the Energy Performance Certificate enables the end user of the building to see how Energy Efficient the building is. The Energy Performance certificate is very easy to understand at first glance whereas the SAP Calculation contains a lot of detailed calculations and figures.

The two are linked though as the Energy Performance Certificate is calculated using the information contained within the SAP calculation.

By providing us with the dwelling drawings and details requested on our SAP data form, we provide you with your SAP Rating certificate. All our SAP Ratings utilise Building Research Establishment (BRE) approved software and are fully submittable to building control.

SAP is also used within Part L1 building regulations compliancy for domestic dwellings. We offer a complete service for Part L1A & L1B compliancy through carbon dioxide emission rates (TER vs DER). Not only will we provide you with your compliancy assessment but if required recommendations and outline specification to achieve compliancy.