How to make old wood windows energy efficient

Share With
How to make old wood windows energy efficient

Windows are a classic feature when it comes to period properties and without them, the house could lose character and charm. However, old wooden windows are almost guaranteed to be single glazing and are known for having issues with draughts, which means they’re less likely to maintain the home’s heat and, in turn, ramp up utilities and increase your carbon footprint.

Today we look at how to make old wooden windows energy efficient with a focus on sash window restoration. 

It might be time for repairs to your window frames

Before thinking about sash window double glazing or draught-proofing, consider repairing your sash window frames. It’s still cheaper than replacing an entire window, and quite honestly the starting point for any sort of restoration. Without undertaking repairs to the wooden window frames, there’d be little point to draught-proofing or having the double glazing installed as partly decayed wooden frames might not be able to hold the extra weight of double glazing and as the timber is what holds everything together, it’s important to make sure it is in sound condition.

repair timber frame
repair wimber frame

The great thing is, by simply revitalising your windows, you can expect enhanced aesthetics alongside increased energy efficiency whilst still preserving the traditional charm. 

It’s also worth checking on your locks and fasteners, especially with sash windows where keeping them sealed securely is half of the battle won in saving energy. 

Think about double glazing retrofitting

Historically, before the days of double glazing, homes had wooden shutters built on the inside and when shut, offered some protection against draughts. Later, this would become heavy curtains or roller blinds and yet, nothing quite compares with the insulation of double glazed windows.


Switching from single to double glazing doesn’t have to influence the look of your windows and when done properly, won’t change the aesthetic of your home at all.

That’s thanks to various new technologies in glass and ultra-thin double glazing products now available from multiple companies. Especially not when you have a product like Fineo ultra-thin double glazing installed.

With the look of single glazing, but all the benefits of having two panes of glass, you can save up to £150 a year on energy.

This is because where other double glazing options are filled with gas that slowly evaporates over the years, making them less energy efficient, Fineo double glazing units employ a different technology which removes the air between glass panes to create a vacuum. This essentially plays the same role as gas by keeping the heat inside but, unlike gas, it does not disappear after five years. Fineo has a fifteen-year guarantee for double glazing units, so you can be confident in what you’re having installed.

If you are thinking about installing Fineo, or any other double glazing, we highly recommend having it done by a professional as windows would need removing.

Draught-proof your window

It’s always important to remember that wood is an organic material and over time could swell, shrivel, flake or decay. It also isn’t unusual for wooden windows to warp, which often leaves your frames with gaps that result in draughts. With warm air escaping and cold air rushing in, keeping your house warm can become an uphill battle. 


Luckily, there are plenty of affordable sash window draught-proofing solutions. The most common way of sealing up those gaps is to simply use draught-sealing strips and compression seals. However, it’s important to retain ventilation where it’s needed. Don’t accidentally seal up trickle vents, and keep ventilation in high moisture rooms. 

When you’re using strips, it’s best to cut them to the exact size. Too long could scrunch them up, making it very difficult to open your window and too short won’t seal the gap properly. For sash windows, it’s also best to use the metal or plastic strips with bristles.

Read more articles