Thousands of listed buildings, including the Houses of Parliament, may be required to install the archetypal suburban windows if proposed changes to Part L of the regulations are adopted.
A palace insider told Building: “We won’t change our windows. We have sealed them in the past to make them more energy-efficient and draught-free but we won’t be changing them. Ninety per cent of our windows are traditional oak and softwood box sash and around 5% are original post-war Crittall steel frame. They are staying put.”
The proposed regulations would come into play if windows in a listed building had to be replaced. Instead of using a replica of the original window, a more energy-efficient version would have to be used.
John Fidler, head of historic buildings conservation at English Heritage, said: “It’s very bad news. These are special buildings and they will be wrecked if these changes go ahead. The standards are impossible to meet with traditional steel and wood products.”
Instead, the buildings may be required to install the plastic windows to comply with EU standards. These rules, which stipulate a minimum value for heat loss, in effect rule out timber sash and steel-frame windows.
Jennifer Turner, director of the Steel Window Association, added:
“If this amendment goes ahead, it will change the face of English cities.
“In Whitehall for example, all the buildings have steel windows and these would have to be replaced with PVCu.”
Fidler said the rules would affect 500 000 listed buildings including, for instance, textile mills in Manchester that are due to be redeveloped as apartments. Under the proposed changes, the mills would not be allowed to retain their 19th-century windows.
“What English Heritage bitterly regrets is the prescriptive way the proposed regulations are drafted,” said Fidler.
John Pyatt, managing director at Crittall Windows, Europe’s largest steel window manufacturer, said: “My fear is that if the proposed change is not amended then we will gradually see our heritage buildings from the 1920s and 1930s permanently disfigured by the installation of inappropriate and unsympathetic fenestration.”
A spokesperson for the DETR said: “This is a consultation document and we will be considering all responses to the proposal as part of that consultation.”
The consultation period ended on 29 September.
