Nowhere left to hide on Part L

Graham Howatson
Graham Howatson

The end of the Part L transitional period is looming fast on the horizon with big ramifications for installers who work with housebuilders.

New build is competitive. Orders frequently go to the lowest tender. The net result is that lower cost PVC-U and aluminium systems have historically had greatest reach.

But five months on from regulatory changes, the realities of Part L are changing as targets for energy efficiency drive a shift in priority.

“Smaller housebuilders were going through a little bit of a shift in mindset towards added value products before the revision of Part L came in in June. What it’s served to do is to accelerate it,” says Graham Howatson, director at specialist fabricator, HWL.

“Rising energy costs have made home energy efficiency a selling point,” he continues. “Combined with the regulatory requirement to deliver more energy efficient homes, they’re specifying better performing windows but also giving more attention to their appearance.”

Changes to Part L introduced new, notional u-value requirements for new build windows and doors with a glazed area of more than 60%, of 1.2W/m2K. Coming into effect from June 15 2022, the update allowed for a 12-month transitional period through to 15 June 2023.

“If you’re breaking ground before 15 June 2023, you don’t have to hit the new regs,” Graham says. “That transitional grace and favour period has effectively delivered a stay of execution for those systems which don’t get down to1.2W/m2K.

“Developers have still been able to place orders for less energy efficient systems and still comply as long as they’re on site by before that date.

“We’re now entering a phase where our customers are being asked to quote for jobs which push beyond that period into the second half of 2023 – and without exception, they’re being asked for the Part L notional U-value of 1.2W/m2K.
“A lot of the systems, particularly the aluminium ones, which have historically had a stranglehold on new build just don’t get there,” Graham continues.

He also points out that based on direct feedback from customers in the new build sector, developers are disregarding the limiting u-value of 1.6W/m2K for new build.

“We should simply stop thinking about the limiting u-value in new build because it isn’t happening,” Graham says. “In theory, you could fit a window in a new build project with a of u-value of 1.6W/m2K as long as the developer is prepared to up the specification on wall or roof insulation or something else.

“But that’s not happening. Developers are already specifying the notional u-value of 1.2W/m2K for projects which break ground after 15 June next year.

“If you can’t offer 1.2W/m2K you’re not going to be in new build.”

HWL specialises in premium PVC and aluminium products, including Residence Collection and the Sheerline Prestige range.

“In the past R7 hasn’t been seen as a new build window because of price point. It’s not expensive but it costs more than run-of-the-mill systems,” Graham says.

“But as housebuilders become more focussed on selling added value benefits and as regulation drives a shift in expectations of performance, so R7 has become a far more competitive proposition in a newbuild environment.”

“Again, Sheerline is a mid-to-premium market system,” Graham adds. “A lot of housebuilders wouldn’t necessarily have looked at it because there are – or were – cheaper systems on the market.

“With the shift to 1.2 W/m2K from the second half of 2023, those cheaper aluminium systems fall short, so the dynamic is changing across the board.

“Windows, bi-folds, sliding doors – those older systems, the ones which have muddled along since June 2022, working around system shortfalls because of the transitional arrangements – they aren’t going to win you business from now on.”