5 ways to improve thermal efficiency of timber windows

When looking to improve the thermal efficiency of your home, upgrading your windows can make a big difference

The Sash Window Workshop period timber windows
(Image credit: The Sash Window Workshop)

A period home can be a joy to own – the original features, charming character and history of the property are all unique selling points. However, when the colder months set in, homeowners of older homes might worry about how warm their house will be through winter. Luckily, when looking to improve the thermal efficiency of your home, upgrading your windows can make a big difference, both visually and practically. 

Depending on the condition of the windows, and whether your building is listed, there are various options available to help improve the thermal efficiency of original timber windows. The Sash Window Workshop have shared the key things the owner of a period home might want to consider when it comes to repairing and replacing traditional windows.

1. Draught proofing

Assuming your timber windows are still in a good condition, the cheapest way to improve the thermal efficiency of them is to have them draught proofed. Draught proofing involves sealing the gaps between the moving parts of the window (the sashes) and the window frame. This will reduce heat loss, stop the window rattling in the wind and prevent cold draughts coming in during the winter months.

Unlike replacement windows, draught proofing qualifies for a reduced rate of five per cent VAT for homeowners.

2. Complete new double glazed timber windows

As long as you are not restricted by planning regulations, installing complete new double glazed timber windows can make a huge difference to thermal efficiency and is a great option where draught proofing isn't possible, or if the windows are in need of repair.

Double glazing works by creating a space of insulating air or gas between two panes of glass to reduce heat loss. As long as the windows are manufactured and installed to a high standard, they should reduce draughts and improve heat retention, making your windows more thermally efficient.

The Sash Window Workshop period timber windows

(Image credit: The Sash Window Workshop)

3. New sashes into the existing window frames

If the frames of your timber windows are still in a good condition, a window company with experience working on period properties should be able to just replace the moving parts of the window (the sashes) with double glazed sashes. This is more effective than draught proofing alone, and also means the panes lose less heat, too.

These should be draught proofed on installation and should provide you with the same benefits as complete new double glazed windows. However, it is important to ensure that the company has experience working on similar properties as this work requires a high level of attention to detail to ensure that the new sashes fit and operate smoothly in the existing window frame.

The Sash Window Workshop period timber windows

(Image credit: The Sash Window Workshop)

4. Secondary glazing

If you are unable to install double glazing, due to living in a listed property, you may want to consider installing secondary glazing.

Secondary glazing involves installing a second pane of glass and frame inside the existing window. It is designed to provide increased energy efficiency, while retaining the existing external windows, and has been found by Historic England to cut heat loss by around 60 per cent.

The Sash Window Workshop period timber windows

(Image credit: The Sash Window Workshop)

5. Obtain quotes

When obtaining quotes, it is important to check that the company has experience carrying out the type of work you want on similar properties. Ask to see examples of similar work and request a tour of their workshop to see first-hand the quality of the windows that they are manufacturing for other customers. This will ensure your home is fitted with sympathetic windows of the quality your property deserves. 

Check whether the work would require planning permission. If you live in a listed building or an Article 4 conservation area, check with the council what work they would be more likely to approve.

About The Sash Window Workshop

The Sash Window Workshop have extensive experience manufacturing, installing and draught proofing timber windows in period properties. Established in 1994, they have worked in various conservation areas across London and Southern England and understand the importance of paying extraordinary attention to detail when upgrading windows in traditional homes. To obtain a free, no obligation quotation to upgrade your timber windows, contact The Sash Window Workshop on 01344 868 668.