Part L: Time is running out

Nigel Headford, director of Deceuninck Aluminium

Deceuninck Aluminium has predicted a ‘ticking time bomb’ for manufacturers of less-energy-efficient systems, suggesting that they could be ‘left high and dry’. The ministry of housing communities and local government (MHCLG) is expected to publish new standards for energy efficiency in the autumn. As a result, manufacturers of aluminium windows and doors could find all, or part, of their product offer falls short of changed building regulations – effectively locking them out of the market within a matter of months.

“We’re not over playing this when we say it could lock some fabricators, or at the very least some of the products that they manufacture, out of the market,” said Nigel Headford, director of Deceuninck Aluminium. “There are a lot of aluminium products which, as it stands, only just scrape in under Part L energy requirements.

“If Part L now goes to U-values of 1.4W/m²K, some older systems aren’t going to make the grade, and fabricators could find that something that they have supplied for a decade falls short, excluding it from the market almost overnight.” A revision of Parts L and F of building regulations is expected in October, as part of the future homes standard.

Although the detail is still to be published, consultation documents proposed a tightening of standards: new minimum U-values for windows of 1.4W/m²K, from the existing 1.6W/m²K. For doors, the step change is even greater, with the same new U-value of 1.4W/m²K but from the pre-existing 1.8W/m²K.

“There are aluminium bi-fold and inline sliding systems out there that struggle to achieve a U-value of 1.6W/m²K. You can maybe bump up your glass spec’, but it’s going to make to your product uncompetitive,” continued Nigel. “If things move to 1.4W/m²K, systems companies are either going to have to move exceptionally quickly to redesign their products, or fabricators are going to have to switch suppliers.”

Consultation on the future homes standard closed in January. Though the time frame has potential to slip, the MHCLG is expected to release its revision of Part L in October, coming into effect in April 2022.

Driven by the UK’s pledge to cut carbon emissions, including improving the energy efficiency of existing and new homes, proposals set out in the consultation document suggest a significant step change will be required across a wide range of building products, including windows and doors. Launched at the beginning of 2020, Decalu, by Deceuninck Aluminium, is an ultra-energy efficient window and door offer.

The Decalu range includes the Decalu88 bi-folding door, which achieves U-values as low as 0.68W/m²K; the Decalu163 lift-and-slide, which hits U-values as low as 0.8 W/m²K; and the Decalu101 Scand, which offers U-values as low as 0.89W/m²k.

“There are lots of other reasons to manufacture or fit our products, manufacturing efficiencies of 30-40% over other premium systems; co-extruded, pre-inserted gaskets; dual, textured and marine-grade finishes as standard, and masses of end user and trade appeal,” said Nigel. “That’s important.

“But being able to meet and significantly exceed current and future building regulations is critical. As a fabricator, right now, I’d be asking some pretty serious questions of my aluminium systems supplier.”

For more information about Deceuninck Aluminium’s offer, call 01249 816 969, email or visit

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