The future of the SAP model

The Department for Business, Energy and Industrial Strategy (BEIS) is currently reviewing the Standard Assessment Procedure (SAP) model, which is used to assess the energy performance of homes.

You may have come across SAP calculations before, but we’ve pulled together a quick reminder:

What is SAP?

SAP determines a carbon emission target for a building based on data such as construction type, fuel source, type of heating and orientation. The calculations are based on:

  • Construction materials and thermal insulation of the building fabric
  • Air leakage and ventilation equipment
  • Efficiency and control of heating systems
  • Solar gains
  • Choice of fuel for space and water heating, ventilation and lighting
  • Space cooling
  • Renewable energy technologies

Since 1995, a SAP rating has been required for all new homes under Part L of the building regulations, so most property developers will be familiar with it. For those new to the building industry, it will be a new and often challenging aspect of the process!

Why does SAP matter to you?

The assessment is used to produce Energy Performance Certificates (EPC) which are required for all buildings when built, sold or let. EPC ratings are more important than ever, as new regulations are coming into force next year which will make it illegal for a landlord to rent a property with a rating lower than E to a new tenant.

An EPC pass is achieved by meeting targets around:

  • How well the fabric of the dwelling contains heat
  • Solar gain
  • Quality of construction and commissioning of systems
  • Predicted CO2 emissions from the dwelling

SAP provides the route to compliance and all new houses must meet the carbon emission target provided. It’s a key tool in driving CO2 reduction in buildings and is used as the primary tool for near-zero carbon building by 2020.

Why is SAP being reviewed?

It has been suggested that the current model discriminates against older properties and makes it difficult for owners to make suitable energy investments, with owners being compelled to make improvements that are not suitable for properties of a certain age and construction.

Also, some say there is a mismatch and lack of consistency between SAP assessments and property surveys. The language within SAP is different to that within a common survey; for example, SAP uses the term ‘heat loss wall’ whereas surveying says ‘external wall’.

Many suggest that the new model needs to consider all factors that affect energy in the home, such as radiator reflectors and occupation patterns.

What do you think about the current SAP model? The review case is open until the end of this month (January); we’d love to hear your thoughts.

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