Sash Window Draught Proofing London
Eliminate Draughts · Stop Rattles · Cut Heat Loss
We fit concealed brush pile seals into your original timber sash windows — routing them flush with the frame so they're completely invisible. Draughts, rattles, and cold spots gone in a day. Fully accepted in conservation areas and listed buildings. Free site survey anywhere in London.
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What Is Professional Sash Window Draught Proofing?
Sash windows — even well-maintained ones — lose heat and admit draughts through three main points: the gap around the meeting rail, the channels the sashes slide in, and the gap at the top and bottom of the frame. In a Victorian terrace, the combined draught from all windows can account for 20–30% of total heat loss.
Professional draught proofing closes these gaps permanently using concealed brush pile seals routed into the timber — not surface-applied foam tape that perishes within a year. The result: up to 50% less heat loss through your windows, no rattling, no cold spots, and no visible change to the appearance of your windows.
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How We Draught Proof Your Sash Windows
We use a three-step process developed specifically for original timber sash windows:
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1Identify All Gap Points
We examine every gap — meeting rails, sash channels, parting beads, top rail, and bottom sill — to locate all draught entry points before any work begins. -
2Select the Right Seal for Each Location
Brush pile seals for moving sash channels; wool or foam compression seals for fixed areas like top rails and sills. Each location gets the correct seal type for a lasting result. -
3Route and Recess — Completely Concealed
We route a precise channel into the timber frame and recess the seal flush with the surface. Completely invisible from inside and out. The window continues to operate exactly as before — just without the draughts.
Three Benefits You'll Notice Immediately
Improved Energy Efficiency
Professional draught proofing can reduce heat loss through sash windows by up to 50%. Most London homeowners notice a significant difference in room temperature within the first winter — and see lower energy bills to match.
Eliminate Rattling Sashes
Rattling sashes are caused by loose-fitting sashes vibrating in their channels. The brush pile seals hold the sashes firm without impeding their movement — eliminating rattle completely. For maximum noise reduction, see our soundproofing service.
Increase Internal Comfort
Eliminating cold air infiltration around windows removes the uncomfortable cold zones near window seats and bay windows that make rooms feel colder than the thermostat reading. The entire room becomes noticeably more comfortable.
Conservation Areas & Listed Buildings
Draught proofing is one of the very few energy efficiency improvements that is fully accepted in Conservation Areas and Grade II Listed Buildings — because it makes no alteration to the external or internal appearance of your windows.
Our concealed brush pile system is specifically designed for period timber sash windows. The seals are routed into the existing timber and sit flush with the frame — invisible to any observer and with no impact on the original character of the window.
No planning consent is required. We work across all London conservation areas and have extensive experience with listed building requirements.
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How Much Does Draught Proofing Cost?
Draught proofing is the most cost-effective improvement you can make to original sash windows. Typical costs in London:
- Draught proofing only — from £250–£350 per window
- Draught proofing + re-cording — from £350–£450 per window
- Full restoration (draught proof + timber repairs + re-cord) — from £500–£800 per window
Most London Victorian terraces (8–10 windows) can be fully draught-proofed in one day. We always provide a fixed, written quote after a free site survey — no surprises.
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Real Reviews from London Homeowners
Don't take our word for it — here's what customers say about our sash window draught proofing service.
Why Choose Golden Ratio for
Sash Window Draught Proofing?
We don't use foam tape. We use the professional concealed system — the one that actually lasts and actually works.
Completely Invisible
Seals are routed into the timber and recessed flush with the surface. No visible foam, tape, or external fittings. Your windows look exactly as they did before.
Conservation Area Approved
No planning consent required. Our concealed system makes no alteration to external appearance and is accepted by all London conservation authorities and heritage bodies.
Up to 50% Less Heat Loss
Our professional system seals every gap point — meeting rail, channels, top rail, bottom sill. Not just the obvious ones. The result is a measurable improvement in thermal performance.
Eliminates Rattles
Brush pile seals hold sashes firm in their channels without impeding movement. Rattling sashes become a thing of the past. Works in conjunction with our soundproofing service.
4.9★ — 150+ Reviews
Over 150 five-star Google reviews from London homeowners. Our reputation for quality workmanship and genuine results is our strongest selling point.
All London Boroughs
Based in North London (N7), we cover all of Greater London — Islington, Hackney, Camden, Haringey, Kensington, Chelsea, and every borough in between.
Sash Window Draught Proofing FAQs
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How much does sash window draught proofing cost in London?
Professional draught proofing in London costs £250–£350 per window for draught proofing only, rising to £350–£450 when combined with re-cording. A full Victorian terrace of 8–10 windows typically costs £2,500–£3,500 fully draught-proofed. We provide a fixed written quote after a free site survey with no surprises.
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Will draught proofing change how my windows look?
No — our system is completely concealed. We route a small channel into the timber frame and recess the brush pile seal flush with the surface. From both inside and outside, the windows look identical to before. There is no visible foam, tape, or fittings of any kind.
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Can I draught proof sash windows in a conservation area or listed building?
Yes — concealed draught proofing does not alter the external appearance of your windows and is fully accepted in conservation areas and listed buildings. It is one of the few energy improvements you can make without planning consent. We work extensively in all London conservation areas.
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How long does sash window draught proofing take?
A single window typically takes 2–4 hours. A full Victorian terrace of 8–10 windows is usually completed in one day. There is minimal disruption — we work from inside and windows remain functional throughout the process.
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Is professional draught proofing better than DIY draught excluders?
Significantly better. DIY foam tape and stick-on excluders are surface-applied, visible, and typically last one to two years before perishing or detaching. Our concealed brush pile system is routed into the timber and lasts indefinitely. It also seals every gap point — not just the ones you can easily reach. The performance difference is substantial.
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Will draught proofing stop my sash windows rattling?
Yes — in most cases completely. Rattling sashes are caused by loose-fitting sashes vibrating in their channels. The brush pile seals hold the sashes firm without impeding their movement, eliminating the rattle. If noise from the street is also a concern, see our soundproofing sash windows service for a combined solution.
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Should I draught proof or restore my sash windows?
Often both — draught proofing is included as standard in our full restoration service. If your sash cords are broken, timber is damaged, or windows are stiff to operate, a full restoration is the right answer. If the windows are structurally sound but draughty and rattling, draught proofing alone may be sufficient. We'll advise honestly after the free site survey.
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What areas of London do you cover?
We cover all of Greater London. We have strong experience across North London (Islington, Hackney, Haringey, Camden, Finsbury Park, Stoke Newington, Highbury, Holloway, Hornsey, Muswell Hill), Central London, and West London. Contact us to confirm coverage for your specific postcode.
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Draught Proofing Survey
One window or a full house — get in touch for honest advice and a free, no-obligation quote anywhere in London.
218 Hornsey Road, London, N7 7LL
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