Understanding SAP 11 and Its Significance for Electric Heating Specifiers

Over the next couple of years, a major transformation is coming in the realm of energy efficiency assessment for housing in the UK. The existing Standard Assessment Procedure (SAP) is poised for an extensive revamp with the advent of SAP 11.

Previously, when the SAP was last modified, the carbon factor of electricity witnessed a substantial reduction, propelling the potential of electric heating by framing it as a low-carbon heating source. The impending updates, slated for release before 2025, are projected to be even more impactful, fundamentally revolutionizing heating and building practices across the UK.

Let's delve deeper into the concept of understanding SAP 11 and its possible impact on the electric heating industry.

What is SAP and How Does it Operate?

SAP, an acronym for the Standard Assessment Procedure, was instituted in 1992 by the Building Research Establishment (BRE) as a technique for assessing the energy efficiency of residential properties.

Although SAP does not constitute a regulation or a law, it serves as a metric for evaluating the various elements that influence the energy performance of homes in the UK. It is extensively incorporated in UK building legislation as the principal assessment method. SAP is currently utilized for generating the necessary information for Energy Performance Certificates (ECPs) and demonstrating compliance with the energy conservation requirements of Building Regulations Part L.

SAP 11 represents a comprehensive modernization of the SAP system designed to mirror the prevailing political and technological conditions in the UK. It will accommodate emerging technologies such as smart meters, heat pumps, solar panels, and renewable storage, among other innovations introduced by the UK's building and energy sectors over the past few years.

The SAP 11 modifications will allow for more precise evaluations of UK homes, while directly advocating the government's policy goals for net zero emissions, energy efficiency, and the decarbonisation of heating.

Implications of SAP 11 for Existing Homes

With the introduction of the Minimum Energy Efficient Standard (MEES) Regulations in 2018, commercial rented properties were required to have an EPC rating of E or above for leasing. However, since April 2023, the MEES has been expanded to encompass all privately rented properties, including domestic rentals. By 2025, it is anticipated that the minimum EPC rating will be raised to C for new leases, and by 2028 for all leases, whether new or renewed.

The SAP 11 alterations will affect the EPC rating for many rental properties, potentially making it challenging to achieve the minimum EPC rating. It is suggested that immediate action for retrofitting rental properties to meet these standards could help mitigate costs.

SAP 11's Influence on Future Heating

As SAP 11 consultations are ongoing, the BRE and the Department for Energy Security and Net Zero (DESNZ), in conjunction with various organizations and individuals in the industry and academia, are shaping the new methodology. A recent report provides insights into the prospective changes and their repercussions for future heating. The key areas of change impacting future building and heating include:

Long-Term Carbon Factors A major proposed amendment is the switch in the carbon factors used from short-term evaluations to long-term assessments spanning up to 25 years. This adjustment will support the use of direct electric heating and heat pump technology as the carbon factor for these two heating methods will decline over time, unlike that of a gas boiler.

Residential Demand Side Response

The new SAP proposals recommend the inclusion of an output related to peak energy demand and demand side response management, comparable to the National Grid ESO scheme executed in early 2023. Emphasis will be on smart technologies that enable homes to adjust to peak energy demand, resulting in a more flexible, lower carbon national grid.

Building Form Factor

The existing SAP techniques have consistently underplayed the space heating efficiency in new constructions. The proposed changes are designed to rectify this, leading to more accurate evaluations. This might also have an effect on the building form factor - the surface to volume ratio - as the inefficiencies of buildings with higher form factors will be captured more accurately. As a consequence, heating systems that are typically more complex to install may become popular again, as buildings with lower form factors reduce installation complexities. This could support the growth in the number of challenging-to-install heat pumps.

Improved Domestic Water Modelling

The current SAP measurements could enhance its modelling of domestic water heating, which currently accounts for around 20% of total heat demand. The SAP 11 proposals suggest introducing more variables for a more comprehensive picture. For instance, the peak load demand for hot water can be up to ten times higher than space heating peak demand, which could have substantial implications for water heating design. Efficient water tanks that store hot water for use throughout the day can diminish peak demand and align with renewable energy generation to heat outside peak hours. An improved SAP model for the impact of hot water storage on a building's performance, as suggested by the proposal, could lead to a rise in immersion heaters for hot water.

The SAP 10.2 will continue to be the standard until the SAP 11 changes are finalized following the consultation period. For more information, consider signing up for our "How to Specify Electric Heating CPD." As we eagerly await the impact of SAP 11 on the future of heating and energy efficiency, it's crucial for electric heating specifiers to stay informed and prepared for these upcoming changes.