European Scene: January-February 2011
By John Roper
New regulations for U.K.’s window manufacturers
By John Roper
Windows that have not been formally energy rated under the Window Energy
Rating scheme (WERs), or have not received a formal U-value, can still
comply with the building regulations that came into effect on Oct. 1.
Windows that have not been formally energy rated under the Window Energy Rating scheme (WERs), or have not received a formal U-value, can still comply with the building regulations that came into effect on Oct. 1.
In a letter sent to its members before the switch, Fensa offered two ways that fabricators could prove that their products achieve a U-value of 1.6 W/m2K, which do not require costly formal processes.
In the lead-up to Oct. 1, when the new regulations were due to come into force, the British Fenestration Rating Council (BFRC), the U.K.’s national system for rating energy efficient windows, had been promoting the Window Energy Rating scheme (WERs) as the preferred method of proving compliance with the building regulations – the government announced that windows with a WER of at least a C (up to a possible A) will comply. The alternative U-value method, which has received far less publicity, has been touted as being far more onerous. In both cases, expensive formal testing, calculations and registration are required.
However, fabricators were told that Fensa inspectors would require no formal evidence of compliance if their timber (70-millimetre depth minimum) or PVC windows were constructed using soft coat low-e glass, warm edge spacer (16-millimetre minimum), and 90 per cent argon gas, “i.e., there will be no need to provide further evidence to the consumer or to the Fensa inspector, providing there is no evidence to suggest that our assumption is incorrect.”
The letter also gave details of an online U-value calculator that can determine the whole window U-value. Available from mid-September 2011, the calculator will store the details on a database alongside results from other authorized calculators. “These details will be passed to our inspectors when you, at the point of registration, indicate that the installation conforms to a particular calculation held in our database,” the letter explained. It will cost C$318 (£199) a year to use, for an unlimited number of calculations.
Giles Willson, a director of the BFRC, told The Glazine: “The standard unit as per the press release two weeks ago installed in timber and five-chamber PVC-U systems will achieve a 1.6 U-value. This is not the only solution to achieve compliance – i.e., I know some three-chamber systems will achieve the 1.6 with this spec unit, and other systems will achieve 1.6 without soft coat or gas or warm edge spacer bars.
“This is a spec which will work and is proven in making life for compliance easier for large sectors of the market. The fact a more cost-effective solution may be available by using WER or U-value calculation is down to the manufacturer.”
John Roper is the editor for The Installer, The Fabricator, The
Conservatory Installer and Glass Works magazine published in the U.K.