Thermal bridging analysis
In June 2022, sections of the Building Regulations and Standards, addressing the energy efficiency of buildings in England, Wales and Scotland were updated. As a result, lower carbon emissions targets have been set to tackle the so-called Performance Gap between a building’s design and actual energy performance.
In particular, standards are being raised for insulation detailing, at the junctions in a building's envelope, to prevent thermal bridging, which accounts for almost 30% of a building's total heat loss. [1]
What is thermal bridging?
Thermal bridges, also known as cold bridges, are points in a building's thermal envelope where the insulation is compromised, resulting in increased heat transfer between the interior and exterior environments. They occur where there is a break in the continuity of the insulation layer, such as at junctions, corners, or penetrations.
Thermal bridges can adversely impact upon the energy efficiency of a building by allowing heat to bypass the insulation and flow through the path of least resistance. This results in heat loss during the winter and heat gain during the summer, leading to increased energy consumption for both the heating and cooling systems.
Different types of thermal bridges
What is thermal bridging analysis?
Thermal bridging analysis delivers bespoke, comprehensive thermal bridging calculations using specialist numerical modelling software, which generates Psi (Ψ) values for thermal junctions, helping to demonstrate compliance and deliver energy-efficient buildings.
Failure to provide junction calculations within dwellings can lead to poor default values assumed in SAP/SBEM calculations, which can fail standards and assessments.
This can result in failing to gain compliance with the Building Regulations, or requiring additional energy saving measures elsewhere, increasing the cost of construction.
Benefits of thermal bridging analysis
- Reduced heating demand
Addressing heat loss can reduce the demand for heating energy, which can improve occupant thermal comfort and lower associated carbon emissions.
- Tackling reduced internal surface temperature
Thermal bridges impact the inner surface of a construction. Minimising their effects can help mitigate the risk of surface condensation, moisture, mould growth and damage to building fabrics while supporting occupant comfort and health.
- Future Homes Standard compliance
Reducing thermal bridging is critical to achieving net-zero energy-ready (NZER) buildings that meet future standards and deliver building constructability, durability and longevity. - Optimised design process
Optimisation of the design process by preventing last-minute design iterations and project delays can promote cost efficiency. For example, further thermal insulation or improved air tightness to achieve targets and meet building regulations.
Our thermal bridging analysis service
Our engineers work with you to help reduce your building's performance gap. To complete the thermal bridge analysis we:
- Collect information from design teams to build junction details.
- Complete analysis using Trisco calculation software to analyse any complex 2D and 3D junctions. Advising on outcomes.
- Recommend mitigation measures to reduce thermal bridges, where required. Rerunning analysis using updated junction details.
- Provide a final report detailing junction performance for submission to building control.
Changes to Building Regulations: Accredited Construction Details
In 2022, sections of the Building Regulations and Standards addressing the energy efficiency of buildings in England, Wales and Scotland were updated to tackle the so-called Performance Gap.
A notable change was the removal of Accredited Construction Details (ACDs).
Key contacts
David Callaghan
Senior Director - Building Services