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London's trusted window installation service — call us for a free site survey.
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Expert window installation, repair & restoration for Georgian, Victorian and Edwardian period homes across London. FENSA registered, 5-star rated, free site survey.
No obligation · Free site survey · Reply within hours
Fixing rattles, draughts, and broken cords for smooth operation.
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Complete overhaul of period sash windows to their former glory.
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Bespoke, slimline double-glazed sash windows for heritage homes.
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Eliminate draughts, reduce noise, and improve energy efficiency.
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Bespoke, handcrafted traditional timber shutters for heritage windows.
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Fast, reliable emergency glass replacement for sash and casement windows.
Learn More →Don't take our word for it — here's what our customers say about our window installation service across London.
Our window installation service in London blends mathematical precision with time-honoured artistry to deliver bespoke sash windows that stand the test of time.
Consistently praised by London homeowners for quality craftsmanship, punctuality, and transparent pricing. Our reputation speaks for itself.
All window replacements are fully FENSA registered, meaning your installation meets Building Regulations and your home is protected.
We specialise in Grade II listed and Conservation Area compliance across all London boroughs — Article 4 Directions no problem.
As an Accoya Approved Contractor, we offer industry-leading rot-resistance with a 50-year anti-rot guarantee on your new windows.
Our slimline vacuum glass achieves superior thermal performance while preserving the slim heritage glazing bar profiles of your period property.
We visit your property, assess your windows, and provide a transparent, no-obligation quote — no hidden costs, no call-out fees.
A selection of recent projects from our window installation service in London — sash restorations and replacements for period properties across the capital.
Yes! We offer completely free, no-obligation site surveys and technical assessments across all London boroughs. Our experts will visit your property, assess your windows, and provide a detailed quotation.
Absolutely. Golden Ratio Sash Windows & Doors is fully FENSA registered. This means all of our window and door installations comply strictly with current building regulations, and you will receive a certificate upon completion.
Yes, we specialize in heritage properties. We can manufacture exact, period-accurate timber replicas that satisfy strict local council and conservation area guidelines, ensuring your home retains its historic charm.
Yes. We can retrofit high-performance, slimline double glazing into traditional timber frames. This provides excellent thermal and acoustic insulation without ruining the slim, elegant profile of classic sash windows.
Whether you need a sash window repair, full replacement, or heritage restoration — get in touch for honest advice and a free, no-obligation quote.
218 Hornsey Road, London, N7 7LL
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