Thermal Bridging Calculations
As accredited thermal modellers, we can produce bespoke psi-value calculations to achieve an accurate, highly efficient, and cost-effective fabric performance for new-build developments.
Building Standards require the insulation envelope of any heated building to be designed and constructed to limit heat loss through thermal bridging. Builing Regulations via their technical booklets also require thermal bridging to be taken into account as part of energy assessments. Whilst repeating thermal bridges are accounted for within U-value calculations, a separate psi-value calculation is required to assess non-repeating thermal bridges.
Thermal bridging accounts for 20-30% of total building heat losses, which is significant. We work closely with clients and design teams to identify effective measures to reduce thermal bridging. This process also involves calculating the Temperature Factor for each junction, which helps to mitigate the risk of condensation and mould growth at the junction.
Developers currently have three options to account for thermal bridging within SAP Calculations:
1. Use the governments Accredited Construction Details
Currently the most common method of accounting for thermal bridging is to use the psi-values from government Accredited Construction Details; however, these psi-values are average and can be improved upon without difficulty.
2. Use ‘default’ assumed values
Using default psi-values will result in poor thermal performance, making it difficult to comply with the Target Emission Rate without a significant reliance on renewable technology. Applying default psi-values will also significantly increase the energy demand for space heating within SAP making it almost impossible to achieve compliance to the Building Regulations
3. Calculate bespoke psi-values based on the proposed construction detailing
If your proposed construction does not align to the Accredited Construction Details and using default psi-values is not viable (or desirable), then you must calculate bespoke psi-values. You may also choose to calculate bespoke psi-values if you repeatedly build using the same details and specification. Calculating bespoke psi-values will provide a more accurate energy assessment resulting in improved SAP and EPC ratings whilst also delivering significant savings on specification.
Customers who engage with us at design stage can also utilise our in-house enhanced bridging packages which have been created to offer an alternative to Accredited Construction Details. Using bespoke details over significant improvements in thermal bridging performance on a typical dwelling (when compared against Accredited Construction Details). This service is particularly beneficial to architects and designers who are keen to achieve an enhanced ‘fabric first’ solution through improved thermal bridging and U-value performance. Reducing capital costs of other specification items, such as Air Source heat pumps, PV panels and unneccessary insulation.
Building Standards require the insulation envelope of any heated building to be designed and constructed to limit heat loss through thermal bridging. Builing Regulations via their technical booklets also require thermal bridging to be taken into account as part of energy assessments. Whilst repeating thermal bridges are accounted for within U-value calculations, a separate psi-value calculation is required to assess non-repeating thermal bridges.
Thermal bridging accounts for 20-30% of total building heat losses, which is significant. We work closely with clients and design teams to identify effective measures to reduce thermal bridging. This process also involves calculating the Temperature Factor for each junction, which helps to mitigate the risk of condensation and mould growth at the junction.
Developers currently have three options to account for thermal bridging within SAP Calculations:
1. Use the governments Accredited Construction Details
Currently the most common method of accounting for thermal bridging is to use the psi-values from government Accredited Construction Details; however, these psi-values are average and can be improved upon without difficulty.
2. Use ‘default’ assumed values
Using default psi-values will result in poor thermal performance, making it difficult to comply with the Target Emission Rate without a significant reliance on renewable technology. Applying default psi-values will also significantly increase the energy demand for space heating within SAP making it almost impossible to achieve compliance to the Building Regulations
3. Calculate bespoke psi-values based on the proposed construction detailing
If your proposed construction does not align to the Accredited Construction Details and using default psi-values is not viable (or desirable), then you must calculate bespoke psi-values. You may also choose to calculate bespoke psi-values if you repeatedly build using the same details and specification. Calculating bespoke psi-values will provide a more accurate energy assessment resulting in improved SAP and EPC ratings whilst also delivering significant savings on specification.
Customers who engage with us at design stage can also utilise our in-house enhanced bridging packages which have been created to offer an alternative to Accredited Construction Details. Using bespoke details over significant improvements in thermal bridging performance on a typical dwelling (when compared against Accredited Construction Details). This service is particularly beneficial to architects and designers who are keen to achieve an enhanced ‘fabric first’ solution through improved thermal bridging and U-value performance. Reducing capital costs of other specification items, such as Air Source heat pumps, PV panels and unneccessary insulation.