Fabricators who are blindly accepting the U-Value claims being made on aluminium sliders and bifolds could be risking non-compliance with the new Part L and inadvertently misleading customers.
Whether it’s down to naivety, lack of knowledge or simple errors in calculations, I am convinced that some of the claims being made by certain systems companies on their aluminium products are simply not achievable.
This is not just a case of me knocking the competition, it’s a simple case of physics. The best way is to explain that is by showing the level of thermal enhancement AluK had to add to our new S140 sliding door to achieve U-Values of 1.4 double glazed and 1.1 triple glazed, and compare that with the enhancements that were in our original BSC94 which achieved U-Value performance of 1.8.
The thermal breaks in the frame of the S140 are more than twice the size of the BSC94 at 55mm compared with 20mm, and in the sash they are at least 50% larger at 38mm and 48mm rather than 25mm. (The 140mm system depth means these sizes can easily be accommodated).
However, many of our competitors fit thermal breaks in their frames and sashes which are very similar to the BSC94 (in frame depths which are considerably bigger) and yet they are claiming U-Value performance for these products which are almost comparable with the S140. It just doesn’t add up.
Thermal performance figures will obviously be misleading if they are being calculated at larger than allowable sizes, and AluK’s technical department has done a huge amount of work to evaluate the claims being made in the market and to try to establish whether other people’s thermal figures are being calculated to the EN14351 and BFRC sizes as AluK’s figures are. They haven’t got any clear indication on that yet.
I can assure our customers though that AluK’s thermal figures are all calculated to CEN sizes 2000 x 2180mm and all are third party accredited. I’d like to think that all the systems companies supplying sliders and bifolds into the UK market could offer similar assurances.
Perhaps fabricators should be doing more to educate themselves and ask more direct questions of their suppliers about the thickness of the thermal breaks in their door systems and how the figures have been calculated.
There is of course the wider issue of how compliance is being policed and what the implications would be for a fabricator or installer who was fitting products which didn’t actually comply with the new Regs.
But, beyond that there is also the question of the responsibility that we as an industry have to homeowners, developers and housing providers to deliver products which do what we say they do.
According to Keystone’s most recent consumer fenestration report, energy efficiency is still the third highest priority for homeowners looking to invest in new windows and doors (after quality and security) and surely, they have to be able to trust every promise being made by suppliers on the performance of their products?
It’s not just a question of competitive advantage for AluK. I would argue that credibility of the industry, and more specifically the aluminium sector, is potentially at risk if buyers feel that they can’t put their faith in us.
