Can Sash Windows Have Double Glazing?

We’ve all been there. Your neighbours are making a racket. There’s a draught blowing in. Or you just can’t keep your energy bills down. Eventually, you start to look at your windows. Whether they’re letting in cold air or too much noise, double glazing seems like the best option.

If you’ve got sash windows, things could get a bit more complicated. Why? It’s in your interest to preserve them. Read on as we discuss the advantages of double glazing, why sash window owners might find things a bit tricky, and how to get over the hurdles.

Why go for double glazing?

In short, double glazing means using two panes of glass with a small gap, rather than one. It’s become more and more common over the years. So much so that it’s actually a requirement on new homes. Why? There are actually several benefits:

Keeping heat in

Because there are two panes with a gap, double-glazed windows are much better at keeping heat in your home. The small gap, usually less than 20mm, acts as an additional barrier to the outside elements. And it’s surprisingly effective. Double-glazed windows help you keep your home warm through the winter and even cooler in the summer. That’s one of the most popular reasons for having it installed.

Get rid of condensation

That small gap also acts as a barrier between the two panes. This is key when it comes to stopping condensation. Condensation forms when the warm air in your home hits the cold surface of your windows. In short, warm air carries more moisture, which is drawn to cold surfaces.

It looks bad and can even cause a mess when your windowsill becomes damp. With single glazing, it’s almost inevitable, because the single pane of glass will get cold on the inside pretty quickly. With double glazing, the interior pane will be kept warm, because of the air gap acting as a barrier.

Saving money

Going back to its insulation qualities, double-glazing could even help you save money over time. Keeping more heat in means you won’t need the heating on as much. That means less energy used and much smaller bills. It will even work through the summer, because you won’t need air conditioning – or as much of it.

As a side note, that will also reduce your carbon footprint and make your property more attractive to buyers in future.

Noise reduction

Windows are one of the top culprits when it comes to unwanted noise – alongside the neighbours or traffic making the noise in the first place. Double-glazing gives you an extra layer of soundproofing. The second pane of glass and air gap between the panes will block out a lot more noise, so your property will be a lot more peaceful.

Protect your furniture

You might not realise it, but sunlight can damage your fabric or wooden furniture time. The constant UV rays cause materials to discolour and weaken. With an added layer, you’ll cut out a lot more of those rays so your furniture or furnishings will last a lot longer.

Double glazing for sash windows

It’s clear why people want double glazing in their homes. The problem is that not all homes can get it so easily. Because they were made before double glazing, original sash windows have a pretty small gap for glazing in the frame. Standard double-glazing companies won’t be able to install double glazing in these windows without damaging them.

Another issue is listing. Listed properties are protected from any big changes – inside or outside. That includes their windows. To put it simply, you can’t replace or change your windows without getting permission. You might get permission if you can prove that the property will benefit from the changes – and that you’re doing as much as you can to preserve its features.

With that in mind, it’s unlikely that PVC double glazed units would be approved.

Double glazing alternatives

Because of the issues with double glazing on sash windows or period properties, some owners will look for alternatives. There are some options out there, but they do have their drawbacks.

Firstly, window shutters will boost insulation and reduce noise. The downside? They only do so when they’re shut, so it could get a bit dark. A good option for overnight insulation, maybe. The same is true for lined curtains, which add another layer to your windows – but block out light when they’re in use.

Another alternative is secondary glazing. That means adding another pane of glass close to the inside of your windows, but not installing it in the actual window frame. It allows plenty of light in and improves insulation without the need for permission. The main drawback here is that it can just look a bit cheap.

What about repairs?

You might find that repairs make more of a difference to your windows than most of these makeshift options. By restoring your sash windows, you can achieve a lot of the same benefits offered by double glazing. So, repairing the wood, stripping and repainting, and fully draught-sealing. At Fix a Sash, we make sure the frame, rails, sill and joints are all in tip-top condition.

Double glazing for sash windows

Back to the main issue – double glazing on sash windows. Despite the complications, it is possible. If you work with sash window specialists. With the right know-how, they’ll be able to add double-glazed panels to original sash windows without damaging the frame.

They can also help out with permission, clearly outlining how it will boost the property and protect the windows. So, you’ll have the best chance of gaining permission for the double-glazing work.

Give us a call

With the right expertise, you can combine the style of sash windows the efficiency of double-glazing. At Fix a Sash, we can offer you exactly that. If you want to find out more about our sash window repairs or sash window double glazing, give our team a call on 0800 313 4688

This article was written on behalf of Fix a Sash by Pieter Boyce, founding partner of Boulton & Boyce Surveyors. Find out more about their services at Listed Property Specialists.