Common Questions about SAP Calculations

How SAP Works?

• Energy Demand: SAP calculates how much energy the home needs to stay warm.
• CO2 Emissions: It then calculates how much carbon dioxide the home releases based on the energy used.
• Efficiency Score: The home gets a score based on how efficient it is (Energy Efficiency Rating or EER).
• Environmental Impact: It also gets a score for how much CO2 it emits (Environmental Impact Rating or EI).

Who Needs SAP Calculations and Why?

SAP calculations are a critical part of the building process for residential properties, whether new builds, conversions, or significant renovations. They ensure that your project meets energy performance standards, helping reduce carbon emissions and energy costs.

Why Are SAP Calculations Important?

• Energy Efficiency Compliance: Ensure your building meets UK energy efficiency standards.
• Environmental Impact: Reduce carbon emissions and contribute to national climate goals.
• Cost Savings: Energy-efficient homes benefit from lower energy bills, improving marketability
• Certification: Essential for obtaining an EPC, which is required for selling or renting

Who can carry out SAP Calculations?

A SAP assessor is also known as an On Construction Domestic Energy Assessor (OCDEA). They must be accredited and registered with a certification body like Elmhurst.

When Are SBEM or DSM Calculations Required?

• SAP Calculations (for dwellings/residential)
  SAP calculations are used to assess the energy consumption and efficiency of new build dwellings. For apartment blocks or flats, each individual dwelling requires its own SAP calculation.

  Note: SBEM calculations are needed for communal areas within residential developments, such as laundry rooms, shared facilities, and passageways. These types of projects often require a combination of both SAP and SBEM calculations.

• SBEM Calculations (for non-residential)
  Non-residential buildings using energy for heating and lighting must undergo an SBEM calculation. This is particularly relevant for new builds, conversions, or first-time fit-outs where indoor climate conditioning systems such as heating, air conditioning, or ventilation are in use.

• Dynamic Simulation Modelling (DSM)
  DSM is an advanced tool used for more complex buildings or projects requiring a highly detailed energy performance analysis. Unlike SBEM, DSM takes into account dynamic factors such as occupant behavior and weather patterns, offering a more precise analysis of the building's energy usage over time.

  SBEM is suitable for straightforward projects, while DSM is required when an in-depth, dynamic understanding of energy performance is needed, particularly for complex structures or innovative designs.

When are SAP Calculations Required?

SAP calculations are required for new homes, major renovations, and when you need an Energy Performance Certificate (EPC) to comply with building regulations or when selling or renting a property.

Design Stage SAP calculations may also be required as part of a building regulation approval application, this can vary depending on the project and local authority.   

When was first SAP published?

In 1994, SAP was first cited in the Building Regulations as the means of assessing the energy performance of dwellings. In 2007 it was adopted as the methodology behind Energy Performance Certificates (EPCs).