U-values are considered ‘essential characteristics’ for the sake of CE Marking, and will need to be included as part of your Declaration of Performance (DoP).
We offer 3 different services to help joinery manufacturers obtain their U-values and energy ratings for their windows and external doorsets in order to comply with the regulations and meet the demands of the market place. Through our experience within the window industry, and in carrying out thermal calculations and 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.
Basic U-value calculations using BBA Software
Obtaining a precise U-value for a manufactured window or door can be prohibitively expensive for smaller manufacturers. We are able to offer this service to BWF members only to provide a basic U-value calculation to enable them to obtain the figure they need to comply with Building Regulations at a reasonable cost. BWF will then issue you with certificated proof of the U-values of the windows and glass options you submitted.
The BWF can arrange for a British Fenestration Rating Council (BFRC) accredited simulator, 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 10077-2:2012. 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.
Window Energy Ratings
The BFRC Window Energy Rating is calculated using the BFRC Rating equation which gives the numerical BFRC Rating (generally a negative number) that can be converted to an A-G band.
When our simulator has all the required information and has confirmed that your company fulfils all of the requirements of the BFRC Scheme, he will undertake the simulation and advise you of the results. To register this energy rating, an Independent Assessor will need to visit your factory to check on the production process of this particular window and also check the simulation process before signing off the result. Your company can then register this energy rating with BFRC .