In 2021, significant updates were made to Part L of the Building Regulations, marking a pivotal step towards enhancing energy efficiency in buildings across the UK.
One of the key changes introduced was the latest iteration of the Standard Assessment Procedure (SAP), which plays a crucial role in the generation of Energy Performance Certificates (EPCs) of dwellings.
Keep reading to learn more about SAP 10, including the changes it brings, the challenges it presents, and its importance in ensuring compliance with the Building Regulations Part L.
What Are the Building Regulations Part L?
Part L of the Building Regulations focuses on the conservation of fuel and power, setting standards for the energy performance of new and existing buildings.
These regulations are essential for ensuring that buildings in the UK are constructed and maintained in a way that minimises energy consumption and reduces carbon emissions.
Compliance with Part L Vol 1 should be considered during design stages to ensure the dwelling, once built, meets all requirements and can be signed off by Building Control. After completion, the SAP assessment can be lodged, and an EPC produced.
Although there are specific minimum standards within the Approved Document L, there is no single prescribed way of achieving compliance. Rather, the dwelling is measured against a notional target dwelling within the calculation software.
The Role of SAP in Energy Performance
The Standard Assessment Procedure (SAP) is the Government-approved methodology used to assess and compare the environmental performance of dwellings. It provides a framework for calculating a building’s energy efficiency, considering factors such as insulation, heating systems, and renewable energy sources.
The latest edition of SAP is SAP 10.2, written and maintained by the Building Research Establishment (BRE). BRE accredits certification schemes, such as Elmhurst Energy, to produce approved software which calculates and produces outputs in line with these regulations.
SAP 10 is the only methodology that can be used to demonstrate compliance with Part L (Volume 1) of the Building Regulations 2021 and must be carried out by a certified On Construction Domestic Energy Assessor (OCDEA).
Updates to SAP Calculations: SAP 10
The main changes from SAP 2012 to SAP 10 cover the following areas:
- Fabric Performance: Improvements to U-values.
- Heating Systems: Shift from fossil fuels (usually gas) to alternatives, like heat pumps.
- Renewables: Now a less influential part of the calculation due to the expectation of using electricity over gas.
With the anticipation of dwellings using low-carbon (electric) heating systems and increasing the thermal performance of the building fabric, new developments will use considerably less energy than their predecessors.
This is reliant, however, on the electricity being generated from renewables, which is the basis of the Government’s energy strategy moving towards the UK’s statutory 2050 emissions targets.
Challenges of SAP 10
Several procedural changes come with the updates to SAP 10, particularly in the design stages of new buildings across the UK.
More challenging, however, is the introduction of Part O of the Building Regulations. These regulations aim to limit unwanted solar gain during summer periods, providing occupants with adequate means of removing excess heat from indoors.
Part O conflicts with Part L and the SAP calculations required under it, as Part L rewards highly thermally efficient envelopes and high levels of air tightness for optimal energy efficiency. Thus, the conditions of Part L contradict Part O’s for increasing ventilation and heat loss.
Addressing this challenge requires a more holistic view, incorporating both Part L and Part O compliance in the design and development of new buildings. For instance, while openable windows address ventilation requirements per Part O, it’s important to consider that some areas may have higher noise or air pollution, preventing windows from being opened.
SAP Calculations by Stroma Built Environment
Stroma Built Environment’s highly experienced team of SAP energy assessors helps developers across the country to ensure Part L and Part O compliance. We recommend involving us early in your project to eliminate costly interruptions later when construction decisions have been decided and executed.
Whether you need assistance with a single property, a full-scale development site, or anything in between, we can help with:
- Design Stage SAP Calculations: Predicting the energy performance of a building before it is built.
- U-Value Calculations: Assessing the thermal performance of elements within a building.
- As-Built SAP Calculations: Measuring the actual energy performance of a building once it has been constructed.
- Predicted Energy Performance Certificate (EPC): Assigning each property with a SAP score which places it on a band from A to G.
Explore our Energy Performance Services or get in touch to discuss your next project.