U-Value Simulations

Why undertake U-value assessments?

Understanding the U-values of your windows is important to you and your customer knowing how energy efficient your windows are. With the recent hike in the cost of gas and electricity, consumers are demanding more energy efficient products. It is becoming increasingly necessary for architects and specifiers to know the U-value of windows, so that they can calculate the SAP ratings of the walls into which the windows are to be fitted. If you cannot provide U-values, then architects and specifiers may opt to use the windows of a competitor who does have the information to hand.
What will I get from BWF?

Through our experience within the window industry, and in carrying out thermal simulations, the BWF, and its service providers, have built up an understanding of the combination of glass and framing configurations that are likely to give the most favourable U-values. We are able to carry out an initial assessment, and advise you on the likely outcome, should you decide to submit a window for U-value calculation, before you go to the expense of doing so. Once you are satisfied with the results of the initial assessment, we will arrange for the BFRC accredited simulator, who is attached to the BWF, to calculate, by thermal simulation, the U-values of the windows submitted. The sizes and configuration of the windows submitted for the calculation will be agreed beforehand, and the report issued will reflect these sizes. All simulations are carried out in accordance with EN ISO 1077-1:2006 and EN ISO 10077-2:2003.

The reports that are issued are in accordance with that standard, and can be used as formal support when you supply U-value information to potential customers. If you require, the simulator can then go on to calculate the U-values over a range of sizes for the agreed configurations, following which a matrix can be issued reflecting the results for each size. What is involved? Once we have received an application from you, we will arrange for one of our consultants to contact you to ensure your company can fulfil all of the information requirements.

He will finalise how many changes you wish to include in the simulation, such as glass options and timber types. Once our simulator has all the required information, he will undertake the simulation and advise you of the results. BWF will then issue you with certificated proof of the U-values of the windows and glass options you submitted.

For further information, please contact kevin.underwood@bwf.org.uk