City chiefs open the door to new slim-line windows

A BAN on double glazing in listed buildings is to be lifted by the city council, after years of campaigning by residents.

Council chiefs have decided that the controversial rules, which affect hundreds of residents across the city, should be changed in order to counter concerns about the environmental inefficiency of single glazing.

It follows a successful one-year pilot that saw a series of Georgian tenements and a Charlotte Square office fitted with a new "slim cavity" version of double glazing.

However, those properties that have historic or "crown" glass windows will not be allowed to change to double glazing until the original glass is damaged or broken. Around one in ten listed buildings are thought to still use crown glass.

Councillor Jim Lowrie, the city's planning leader, said: "The slim cavity double glazing trial showed a significant reduction in the amount of heat lost can be achieved and didn't alter the appearance of the building to the naked eye.

"These windows can help reduce household bills, cut carbon dioxide emissions and ensure these historically important buildings maintain their natural elegance."

Double glazing was banned in all A and B-listed buildings under planning guidelines because of concerns about the "loss of the original fabric" of historic buildings and the impact on their character and detail.

C-listed buildings have been allowed the slim cavity double glazing and it is this type that will now be allowed in A and B-listed properties following the decision yesterday.

The one-year pilot was managed by sustainable energy company Changeworks, alongside the Lister Housing Co-operative, Edinburgh World Heritage and the city council.

Analysis of the performance of the new windows found a "significant improvement" in the ability to conduct heat.

Historic Scotland and Edinburgh World Heritage said there was a "negligible" difference in the appearance of buildings with old glazing and those with the new type.

Nicholas Heath, senior project officer at Changeworks, said: "We wanted to show how energy saving and building conservation can work together, contributing to climate change and fuel poverty targets while retaining their historic integrity."

A spokesman for Edinburgh World Heritage said: "For Edinburgh this is a particularly important issue as over 75 per cent of the building stock in the city centre is listed."

A spokeswoman for Historic Scotland said: "This research will help inform owners of the best solution for their property when it is appropriate to alter the windows in a listed building."