Sash Window Repair London

Sash window repair in London typically costs £150–£600 per window depending on the fault. Common repairs include sash cord replacement (£100–£150), re-balancing weights, and draught seal replacement (£250–£350 for a full overhaul). Timber rot repairs and glass replacements are quoted on assessment. We offer a free site survey so you know exactly what you're paying before any work begins.

A standard sash cord replacement or draught-proofing job typically takes 2–4 hours per window. A full overhaul — cords, draught-proofing, and minor timber repairs — usually takes a full day per window. Most jobs on a London Victorian terrace are completed in one or two days. More extensive timber splicing or glass replacement may take longer depending on the materials required.

Yes — we specialise in period property and listed building window repairs. Work on listed buildings and within Conservation Areas must be sympathetic and like-for-like. We use traditional methods and materials that meet heritage requirements. We can advise on any planning considerations during your free site survey and provide specifications if required by your local authority.

In most cases, repairing original timber sash windows is better value and more sustainable than replacement — especially for period properties. Original Victorian and Georgian timber is denser and more durable than modern timber. When properly repaired and draught-proofed, original sashes can last another century. Restoration also preserves the architectural character of the building. We'll always recommend the most cost-effective option after assessing your specific windows.

Absolutely. Professional sash window draught proofing can reduce heat loss through your windows by up to 50%. It completely eliminates rattling sashes, significantly reduces street noise, and lowers energy bills noticeably. For severe noise problems, take a look at our soundproofing sash windows service.

Yes — we fit slim-profile double-glazed units into existing timber sash frames. Our double glazing for sash windows retains the traditional appearance while dramatically improving thermal and acoustic performance. This is particularly popular for Victorian and Georgian properties in Conservation Areas where replacing the windows entirely would not be permitted.

In most cases, sympathetic repairs — such as cord replacement, draught-proofing, timber splicing, or re-puttying — do not require planning permission. However, if you live in a Conservation Area or Grade II Listed Building and wish to install double glazing or change the appearance of the windows, you will likely need consent. We always advise checking with your local London council, and we are happy to provide specifications. See our heritage repairs guide for more detail.

Yes — Golden Ratio Sash Windows & Doors is FENSA registered. This means all replacement window and door installations come with FENSA certification, which is a legal requirement in England and Wales confirming that work complies with Building Regulations. Learn more on our sash window replacement page.

We cover all of Greater London, with a particular focus on North, Central, and West London boroughs. You can view the full list on our areas covered page. Contact us to confirm coverage for your specific postcode.

Yes — we are fully insured and offer a comprehensive guarantee on all our joinery, repairs, and glazing work. Please review our terms and conditions for full warranty details. As a FENSA-registered installer, our installations meet the highest industry standards for quality and safety.