Can I put double glazing in a listed building?

Sometimes, with slim profile units in appropriate frames, but it is assessed case by case and secondary glazing or repair with draught proofing is often the route that gains consent more easily.

Do replacement windows need building regulations approval?

Yes, they must meet thermal and safety requirements, and installations are normally certified through a competent person scheme or notified to building control.

Will draught proofing an old sash really make a difference?

It makes a large difference to perceived comfort, because draught, not the glass, is what most people are actually feeling.

What holds up best near the sea?

Materials and hardware chosen for a marine environment. Standard finishes on exposed coastal elevations deteriorate noticeably faster than the same product inland.

Fabric · Cornwall

Windows in old Cornish buildings, balancing warmth, character and what consent will allow

Windows are the element that most changes how an older building reads, which is why they attract more conservation attention than almost anything else. They are also responsible for a large share of heat loss and most of the draught complaints in Cornish cottages. Getting both right at once is possible, but it needs the decision to be made on evidence rather than on a salesperson's product range.

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What consent allows

On an unlisted house outside a Conservation Area, replacement is generally a matter of building regulations rather than planning. Inside a Conservation Area, and on any listed building, the material, the pattern, the profile and the method of opening all become part of the assessment, and a like for like replacement in a different material is frequently refused.

Listed buildings need consent for replacement and often for significant repair
Conservation Areas may have an Article 4 direction removing permitted rights
Original glazing bar profile, horn detail and reveal depth all carry weight
Repair of an original window is usually preferred to replacement

Repair often beats replacement

A Victorian or Georgian timber sash was made from slow grown timber and designed to be repaired in parts. Splicing a decayed cill, replacing a sash cord, easing the box and adding discreet brush seals frequently produces a window that runs beautifully, loses far less heat than it did and keeps the building's character intact. It is also usually the route a conservation officer will support without argument.

Secondary glazing, the quiet winner

For heat, draught and especially noise, well fitted secondary glazing often outperforms a modern replacement unit while leaving the original window untouched. It is reversible, it is normally acceptable on listed buildings and it solves the problem of a coastal or town centre property where traffic and weather both intrude. Its weakness is appearance from inside, which good detailing and slim frames largely address.

When new units are the right answer

Where original windows are gone, or where a previous owner installed poor quality replacements, a properly proportioned new window is a genuine improvement. The things worth specifying are the sightlines, the reveal depth so the frame sits back rather than flush, the glazing bar arrangement and, on exposed coastal elevations, the weather rating and the ironmongery finish, because standard hardware corrodes quickly within sight of the sea.

Frequently asked

Straight answers.

Can I put double glazing in a listed building?: Sometimes, with slim profile units in appropriate frames, but it is assessed case by case and secondary glazing or repair with draught proofing is often the route that gains consent more easily.
Do replacement windows need building regulations approval?: Yes, they must meet thermal and safety requirements, and installations are normally certified through a competent person scheme or notified to building control.
Will draught proofing an old sash really make a difference?: It makes a large difference to perceived comfort, because draught, not the glass, is what most people are actually feeling.
What holds up best near the sea?: Materials and hardware chosen for a marine environment. Standard finishes on exposed coastal elevations deteriorate noticeably faster than the same product inland.

Changing windows in an older property?

Send photographs and the address. We will tell you what consent applies and which option gives you the most comfort for the money.

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