U-value calculations (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective the components of a building’s fabric are as insulators preventing heat from transmitting between the inside and the outside of a building.
A U-value is calculated from the rate of energy transfer through one square meter of the structure divided by the difference in temperature at either side of the structure and the value is quoted as watts per square meter per Kelvin (1°C = 1K) – W/m2K.
The lower the u-value, the great the energy efficiency of the product.
As energy prices continue to soar and the awareness of sustainable buildings continues to grow, performance measures such as u-values are becoming increasingly important.
Compliance with building regulations requires lower than ever u-value performance, which means changes in the design of buildings, both in the use of materials, the make-up of the building elements (cavity walls and double / triple glazing) and the overall make up of a building’s fabric.
Build Check can provide simulation services utilising the latest in modelling software to prepare and calculate 2D thermal transmittances via .dxf or .dwg according to BS EN 10077-2:2017 including optimised approach to radiosity method for cavities.
Reports are available inclusive upon request, of Isotherms, total heat flux, heat flow lines, infra-red radiation, surface condensation and high humidity zones, thermal transmittances, and thermal bridge performances.
From our base of operations in Brill, a UKAS accredited testing laboratory No. 4044, Our engineering team can undertake u-value calculations for windows and doors to meet the requirements of the building regulations, Part L and help to design a cost-effective research and development programme to help you maximise the performance of your windows and door products to your specific requirements.
If you want to calculate your own u-values to demonstrate Part L compliance, Build Check’s Oracle u-value calculator is available to members on a subscription service.
Window Energy Ratings
Window Energy Ratings (WER) is a scheme first launched by the BFRC (British Fenestration Ratings Council) and Certass launching similar schemes soon after. A WER provides independent verification of how energy-efficient your windows are. The rating system is based on a scale of G to A+, with A+ windows being the most energy-efficient.
We can offer simulation based WER calculations as an alternative to physical testing (e.g. hotbox testing) which gives window manufacturers the advantage of being able to alter product designs to achieve the desired performance criteria in a simple and cost-effective way. On completion of the simulation, you can use the results as part of the certification process to gain an energy rating for your products.