A++ is here… and no, it won’t cook your house, says BFRC
2nd June 2015

The BFRC has launched its ‘A++’ thermal efficiency window label applications process, along with the emphatic rebuttal that high rated windows will not cause a house to overheat …“contrary to some ill-informed comment within the industry.”

Fabricators and system houses now have four months to submit their applications and designs ready for the first licences to be issued from October 1. A full licence can be sought for any new window design, says the BFRC, but some ‘A+’ designs may already qualify, as it explains in its announcement:

“BFRC follows the 10 point band cut-offs illustrated in section 4.2 of Approved Document L1b.  The new ‘A++’ rating will be no different, with ratings starting at an energy index value equal to or greater than +20. This means any BFRC ‘A+’ rated product which achieves 20 or more can be upgraded to an A++.”

BFRC Managing Director Chris Mayne added: “The launch of the BFRC ‘A++’ ratings band – the first in the country – reinforces the message that BFRC is driving technological developments that give homeowners the latest and best in energy efficient windows.”

But he continued: “And contrary to some ill-informed comment within the industry ’A++’ rated windows will not cause homes to overheat.”

The statement goes on to explain under the heading ‘A++ and the overheating misconception’ that only two external factors could cause a building to overheat beyond comfort level – high external ambient temperature and solar gain. In the case of external heat, the higher rated windows would actually reduce the amount of heat leaking inwards and in respect of solar gain, it says: “It is expected that all ‘A++’ windows (and about 70% of ‘A+’) use triple glazing, with two panes of low-e coated glass.  Their solar gain factor is significantly lower than the equivalent double glazed window. So all ‘A++’ rated windows (and the majority of ‘A+’) will actually help to reduce overheating during the summer months and in the winter they will help keep the home much warmer.”

www.bfrc.org