Thermal Bridging Calculations

Thermal Bridging Calculations

What are Thermal Bridging Calculations

Thermal Bridging Calculations is a calculation of psi values to determine heat loss from buildings. Stroma Built Environment uses specialist thermal modelling software to perform the calculation and identify the thermal bridge. We consult with clients to analyse the building details, provide quantitative analysis and advise on the reasons for building heat loss.

Thermal Bridging services – Why choose Stroma Built Environment?

Stroma Built Environment has an experienced team of Thermal Modellers able to model both simple and complex details accurately in 2D and 3D to determine Ψ-values and temperature factors. By engaging with Stroma at the design stage we can analyse any problem areas and recommend solutions to minimize or eradicate the heat loss. Send your drawings to our expert thermal modelling team and we can advise on the most cost effective strategy to reduce thermal bridging issues.

Thermal bridging (also known as a cold bridge) results in heat loss through junctions in the building fabric. The junctions include wall-roof and wall-floor junctions, party walls, corners, cills, jambs, lintels, and any other significant junctions of the building fabric. Their effects are expressed as a linear thermal transmittance value. This is used to arrive at a Y-value: a factor, which allows calculation of the building’s overall heat loss through thermal bridges. Under Part L of the Building Regulations, thermal bridging must be considered in Standard Assessment Procedures (SAP) and Simplified Building Energy Model (SBEM) calculations.

Thermal Bridging and Energy Performance

A thermal bridge can be caused by a deficiency or break in the insulation of a building. In cold climates such as the UK, this causes heat loss through the insulation barrier. The development and tightening of energy legislation has meant that mitigating the impact of heat loss in a building has gained increased importance. Thermal Bridging Calculations can help to maintain the thermal performance of a building by identifying and offering solutions to rectify any heat loss caused by a thermal bridge.

SAP Calculations and the Impact of Part L1A 2013

The assessment of thermal bridge performance has a greater impact than ever before on SAP calculations, due to the 2013 revisions to Part L1A and the stricter energy efficiency and CO2 targets. At present, there are two methods by which thermal bridges can be entered into SAP calculations:

Performance Values

Performance values have been calculated by a person with suitable expertise and experience, in accordance with BR 497 (Conventions for calculating linear thermal transmittance and temperature factors). In this case, the values are not subjected to any penalty factors.

Calculated Performance

Calculated performance cannot be provided to support the assessment. In this case, it is assumed that y = 0.15; this is an onerous assumption that roughly equates to a greater than 50% increase in the heat loss through a junction.

Request a quote for Thermal Bridging Calculations

Contact our friendly Estimating Team to request a quote for Thermal Bridging Calculations for your building stock. You can also select to receive information about our complementary testing and assessment services to allow Stroma Built Environment to provide compliance support throughout your project.

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