Draught-Proofing Sash Windows in Edinburgh: What Works

Edinburgh has thousands of traditional sash and case windows. They are beautiful, they can last for well over a century with care, and they are often the main reason a period room feels cold and draughty. Before you think about replacing them, it is worth knowing how much can be done to the windows you already have.

Where the heat goes

A traditional sash window loses heat in two main ways:

1. Air leakage. Gaps around the sashes, at the meeting rails and at the parting beads let cold air in and warm air out. This is the draught you feel.
2. Through the glass. Single glazing has a high heat loss compared with modern double glazing.

Different fixes deal with each of these.

What the research says

Historic Environment Scotland tested ways to improve a traditional single-glazed sash and case window. Its Technical Paper 1 found that (HES Technical Paper 1):

• Draught-proofing cut air leakage dramatically, by around 86%, even though it did not change heat loss through the glass much.
• Closing the shutters reduced heat loss through the window by 51%.
• Secondary glazing reduced heat loss through the window by 63%.
• Combining measures, such as secondary glazing and shutters, gave the biggest improvements.

In short: draught-proofing fixes the draught, and shutters, heavy curtains or secondary glazing deal with heat loss through the glass.

What draught-proofing involves

Professional draught-proofing of a sash and case window usually means:

1. Removing the sashes and the staff and parting beads that hold them in place.
2. Repairing any rot, loose joints or broken sash cords while the window is apart.
3. Fitting brush or seal strips into grooves routed into the beads and the meeting rails, so the sashes seal when closed but still slide.
4. Rebalancing the sashes with new cords and, if needed, adjusting the weights, so they stay where you put them.
5. Easing and refitting, so the window opens and closes smoothly.

Done well, the window looks the same from the street, rattles stop, and the room feels noticeably less draughty.

Shutters: the overlooked fix

Many Edinburgh period windows still have internal folding shutters, often painted shut. Bringing them back into use is one of the cheapest ways to cut heat loss at night. See our shutter restoration service.

Secondary glazing

Secondary glazing is a second, slim glazed panel fitted inside the existing window. It can be removable or openable, and leaves the original window untouched. It is often a good option where noise is also a problem.

What about replacing with double-glazed sashes?

Slim double-glazed units can be fitted into new or adapted sashes. In a conservation area or listed building, changes to windows can need planning permission or listed building consent, so check with the City of Edinburgh Council first. Repair and draught-proofing are usually acceptable without consent.

Other quick wins

• Heavy lined curtains closed at dusk.
• Repainting to protect the timber and keep putty sound.
• Reputtying loose glass to stop rattles and leaks.
• Fixing sash cords so windows can be opened a little at top and bottom for ventilation, rather than left wide open.

Ventilation matters

Old windows were part of how period homes ventilated. When you draught-proof, make sure rooms, especially kitchens and bathrooms, still have enough ventilation to avoid condensation. Trickle vents are rarely used in traditional sashes, so opening sashes slightly and using extract fans matters.

Frequently asked questions

Does draught-proofing sash windows make a difference?

Yes. Historic Environment Scotland's testing found draught-proofing cut air leakage through a traditional sash and case window by around 86%.

Do I need permission to draught-proof sash windows in a listed building?

Repair and draught-proofing that do not change the window's appearance are generally treated as maintenance. Replacing windows or glazing in a listed building or conservation area may need consent. Check with the council if unsure.

Is secondary glazing better than draught-proofing?

They do different jobs. Draught-proofing stops air leakage. Secondary glazing reduces heat loss through the glass. Using both gives the best result.

Will draught-proofing stop my windows rattling?

Usually, yes. Seals and adjusted beads hold the sashes firmly in the frame.

How long does it take to draught-proof a sash window?

It depends on the window. We confirm the timescale in the written quote.

Warmer windows without losing the originals

We repair, draught-proof and restore sash and case windows across Edinburgh. See our sash window restoration service.

The price depends on the condition of the window and the scope of the work. After a home visit we give a fixed written quote for the agreed work.

Request a site visit