The glazing industry’s bid for a national window scrappage scheme has been labelled a potential threat to thousands of wooden windows which don’t need replacing.

The Society for the Protection of Ancient Buildings (SPAB) and the Institute of Historic Building said the Glass and Glazing Federation’s (GGF) plans, if adopted by government in the future, could put homeowners on the wrong side of the law through the removal of historic windows.

The Wood Window Alliance called the scrappage scheme a simplistic answer to a much more complex problem.

SPAB’s criticism comes as the GGF’s Number 10 petition reached 4,468 signatories by the deadline of March 24.

The proposal, designed to boost sales for the window industry, calls for householders to be granted £1,000 towards the installation of new windows in exchange for scrapping existing poorly insulated ones.

SPAB said the terminology in the petition and that of “scrappage” marketing schemes launched by the likes of Anglian and Everest was potentially misleading.

“If a real scrappage scheme were to be introduced, it could actually have a devastating effect on historic buildings and also on buildings that are not listed, but which have traditional wooden windows,” said SPAB secretary Philip Venning.

“We do need to find ways of improving the energy efficiency of existing housing while respecting well-established principles of architectural conservation,” added Sean Parnaby, chairman of the Wood Window Alliance. “For windows, that means reprairing wherever possible, using authentic materials, and maintaining the building’s character.

Performance Window Group (PWG) chairman Roy Wakeman said he would support a national window scrappage scheme if it helped market demand for fenestration. “Then it would be up to us to sell the benefits of our products.”