Golden Ratio Windows specializes in double glazing retrofits and full timber window restorations across London.
Can sash windows be double glazed?
I get asked this pretty much every single week when I'm out pricing up jobs in old Victorian terraces. Can sash windows be double glazed? The quick answer is definitely yes. You don't need to freeze through another winter or constantly wipe condensation off the glass just because you live in an older house.
A lot of folks panic thinking they need to rip out all their original timber framing and stick cheap plastic uPVC in instead. That's a massive waste if your original box frames are still solid. We just take out the moving parts and upgrade them to hold modern glass. It keeps the front of your house looking completely original while actually keeping the heat inside where it belongs.
Can sash windows be double glazed? The actual process
When someone says to me, Can sash windows be double glazed?, their very next thought is usually about how thick glass is supposed to fit into those incredibly thin heritage frames. We use something called slimline double glazing. It's barely thicker than the single glass you already have, but the insulation is completely different.
We pull out your drafty old sashes and build exact copies using rot-proof timber like Accoya. Then we drop the slimline units in. After that, we re-hang the new sashes back into your original frame and balance them up properly with fresh lead weights so they don't slam down on your fingers.
Can sash windows be double glazed? What you get out of it
It's not just about stopping the cold. Sticking slimline units into your old frames changes how the house actually feels day to day. We run discreet brush seals around the entire edge, which immediately kills that horrible wind whistle you hear in winter. It also cuts out a massive chunk of street noise if you live on a busy road. Obviously, you'll stop throwing money away on heating the pavement outside, and you won't have to deal with dripping wet glass every morning.
In almost all cases, the answer is yes. Whether you live in a standard terrace or a grand Georgian townhouse, the process is usually straightforward. The only exception is if you live in a strictly controlled Grade II Listed building, where you might need planning permission. Even then, many conservation officers now approve slimline heritage double glazing because it looks identical to the original.
If you find yourself still staring at your frames thinking, Can sash windows be double glazed?, just get us round for a quick look. I'll give you a totally straight answer and a free quote so you know exactly what you're dealing with.
FAQ
Will the new windows look bulky?
No, we use slimline units and replicate your exact glazing bars. Once painted, you won't be able to tell they aren't the originals.
Do you have to tear out the whole window?
Not usually. If your box frame is healthy, we only replace the sliding sashes, which saves you a lot of money and avoids messing up your interior plasterwork.
