Thermal bridging and PSI values (heat loss values) are factored into SAP calculations and have a significant impact on Part L compliance.
Thermal bridging relates to the heat lost within the joints of a building and quantifies the amount of heat that escapes (the PSI value). Thermal bridging is often accountable for 15–30% of the total heat loss within a property.
Poor thermal bridging means increased energy demand, making it harder to achieve Part L compliance.
- Some construction types perform better than others, with an abundance of accredited construction details that can be followed to minimise thermal bridging.
- If recognised construction details are not available, default PSI values must be entered. This is likely to cause the SAP calculation to fail on the latest 2021 Part L regulations.
- Constructions that do not have recognised details will therefore require bespoke calculations. This is common with construction types such as system builds, timber frame, steel frame and ICF.
- Bespoke calculations make certain that accurate PSI values are reflected, based on the specific construction details provided.
Get in touch if you require bespoke thermal bridging calculations — our team are happy to help. Start a quote.