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London's trusted timber casement window specialists — call us for a free site survey.

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Bespoke Timber · Accoya® Approved · Made to Measure

Casement Windows London

Master Crafted · FENSA Registered · 50-Year Timber Warranty

London's premier specialists in bespoke timber casement windows. We design, manufacture, and install made-to-measure casement windows for period and contemporary properties across the capital — combining traditional joinery methods with Accoya® high-performance timber. Heritage styles our speciality.

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FENSA Registered Certified Installers
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Accoya® Approved 50-Year Timber Warranty
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Period Specialists Georgian · Victorian · Edwardian
4.9★ Rated 150+ Google Reviews

Get a Free Quote

No obligation · Free site survey · Reply within hours

Opening Hours
Mon – Fri 8:00am – 4:30pm
Saturday 8:00am – 3:30pm
Sunday Closed
Trusted & Accredited
FENSA Registered City & Guilds Accoya Approved Contractor Google 5 Stars Checkatrade
Design · Manufacture · Install

London's Premier Timber Casement Window Specialists

At Golden Ratio Windows, we design, manufacture, and install bespoke timber casement windows across London. Our master craftsmen combine traditional joinery methods with modern technology to deliver windows that are beautiful, thermally efficient, and built to outlast the property they're fitted in.

Whether you're upgrading a period Victorian terrace, restoring a Georgian townhouse, or fitting contemporary casements in a new build — every window is made to measure, finished to your specification, and installed by our own team.

Get a Free Quote
Bespoke timber casement windows installed in a London period property by Golden Ratio Windows
Built to Perform

The Benefits of Our Timber Casement Windows

Every casement window we produce is built to a single standard — the highest. Here's what you get as standard:

  • Superior Energy Efficiency — double-glazed units eliminate draughts and significantly reduce heat loss, cutting energy bills year-round.
  • Fully Draught Proofed — high-quality compression seals prevent rattles and cold draughts from day one.
  • Noise Reduction — premium glazing options significantly reduce London street noise.
  • Uncompromising Security — all windows feature insurance-approved multi-point locking systems.
  • Exceptional Ventilation — hinged casements open fully for excellent airflow and maximum natural light.
  • Low Maintenance — Accoya® timber requires repainting only every 10–12 years, not every 3–5 like softwood.
High-performance timber casement windows fitted in London period property
Made to Measure

Bespoke Styles Tailored to Your London Home

We understand that every property is unique. We offer four main casement styles, all fully customisable:

  • Flush Casement Windows — the traditional choice, where the sash sits flush within the outer frame. Clean lines, ideal for period and contemporary properties alike.
  • Period Casements (Georgian, Victorian & Edwardian) — authentic glazing bar patterns, period proportions, and traditional ironmongery. Indistinguishable from the originals.
  • Double / French Casements — two sashes opening from the centre for unobstructed views and maximum ventilation. Ideal for garden-facing rooms.
  • Casement Bay Windows — angled or square bay configurations to maximise interior light and space.

All styles available in Accoya®, softwood, hardwood, or oak. Finished in your choice of colour or natural timber.

Discuss Your Requirements
Bespoke period casement windows being installed in a London Victorian property
The Science Behind the Timber

Why We Use Accoya® Timber

Accoya® is an ultra-high performance wood made from sustainably sourced timber, modified through a patented acetylation process. The result is timber that is dimensionally stable in all weather conditions — meaning your casement windows will never stick, warp, or swell with the seasons.

Golden Ratio Windows is an approved Accoya® manufacturer — one of a select group of London joiners certified to work with this material. It carries a 50-year above-ground warranty and requires repainting only every 10–12 years.

Accoya® is Cradle-to-Cradle Gold certified for sustainability — the right choice for your home and the planet.

Accoya Approved Manufacturer — Golden Ratio Windows Accoya timber casement windows — dimensionally stable, 50-year warranty
How Does Accoya® Compare?

Timber Comparison: Accoya® vs Hardwood vs Softwood

The upfront cost of Accoya® is higher — but over the life of your windows, it's significantly cheaper to own.

Factor Accoya® Timber Hardwood (Oak / Sapele) Softwood (Pine)
Expected Lifespan 50+ Years (above ground) 30–40 Years 10–15 Years
Swelling & Shrinkage Minimal — 75% less than other timbers Moderate — can stick in winter High — prone to warping
Maintenance Cycle Every 10–12 years Every 5–7 years Every 3–5 years
Warranty 50 Years (above ground) Manufacturer dependent Limited
Sustainability Cradle-to-Cradle Gold Certified Variable (slow growth species) Standard FSC
Our Standards

Manufactured to the Highest Specification

Every casement window we produce is built in our own workshop to exacting standards. We work closely with each client through the design and planning process to ensure accurate measurements and a style perfectly suited to their property.

  • Fully draught proofed with compression seals
  • Inner mouldings scribed and machined to specification
  • Timber pressure-treated against wet rot, dry rot, and wood preservative
  • Available in softwood, hardwood, oak, and Accoya® specialist timber
  • Primed with microporous paint (unless otherwise requested)
  • Supply only, supply & measure, or full supply and fit service available
Timber casement window manufacturing and installation — Golden Ratio Windows London
Heritage Specialists

Conservation Areas & Listed Buildings

Timber casement windows are the preferred choice of planning authorities in London's conservation areas. We have extensive experience producing period-accurate casements that meet heritage requirements for Georgian, Victorian, and Edwardian properties.

For listed buildings, we can produce windows that are like-for-like replacements in every detail — matching original glazing bar profiles, glass types, and ironmongery. We can advise on planning requirements during your free site survey.

Period casement windows for conservation area properties in London
Simple Process

How to Get Your Casement Windows

  1. Get in Touch — fill out the form on this page or call us on 020 3488 1695. We'll respond within hours.
  2. Free Site Survey — one of our London specialists visits your property, takes accurate measurements, and discusses your style options.
  3. Fixed Written Quote — a detailed, no-obligation quote with full specification. No surprises on the day.
  4. Manufacture & Install — your windows are built in our workshop (typically 6–8 weeks lead time) then installed by our own team.
Book a Free Survey
Golden Ratio Windows casement window installation process
What Our Customers Say

Real Reviews from London Homeowners

Don't take our word for it — here's what our customers say about our timber window service across London.

15+
Years in the Trade
500+
Windows Installed
4.9★
Google Rating
32+
London Boroughs Served
50 Year
Accoya® Timber Warranty
Local & Trusted

London's Go-To Experts for
Timber Casement Windows

We combine the craftsmanship of traditional joinery with the performance of modern materials. Every window is made to last a lifetime.

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Accoya® Approved Manufacturer

One of a select group of London joiners approved to manufacture with Accoya® — the world's leading high-performance modified timber. 50-year warranty. No swelling. No sticking.

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Period Property Specialists

Georgian, Victorian, and Edwardian casement windows reproduced to authentic period specifications. Glazing bars, ironmongery, proportions — all matched to your property.

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Insurance-Approved Security

All casement windows fitted with multi-point locking systems that meet insurance requirements. Secure, tested, and compliant with current building regulations.

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4.9★ — 150+ Reviews

Over 150 five-star Google reviews from London homeowners. Our reputation for precision craftsmanship, honest advice, and clean installation speaks for itself.

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Our Own Workshop & Team

Every window is manufactured in our own London workshop and installed by our own team — no subcontracting. One team, one standard, full accountability.

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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.

Got Questions?

Casement Windows London — FAQs

  • How much do timber casement windows cost in London?

    Timber casement windows in London typically cost £800–£3,000 per window depending on size, timber specification, and glazing. Accoya® timber costs more upfront but carries a 50-year warranty and requires far less maintenance than softwood — making it significantly cheaper over the lifetime of the window. We provide a free site survey and fixed written quote before any work begins.

  • What is the best timber for casement windows in London?

    Accoya® is widely considered the superior choice. Unlike traditional softwood or hardwood, Accoya does not swell or shrink with seasonal changes — so windows open and close smoothly year-round. It carries a 50-year above-ground warranty, needs repainting only every 10–12 years, and is Cradle-to-Cradle Gold certified. Golden Ratio Windows is an approved Accoya® manufacturer.

  • Can you match casement windows to a period property?

    Yes — we specialise in period casement windows for Georgian, Victorian, and Edwardian properties. We replicate authentic glazing bar patterns, traditional ironmongery, and period proportions exactly. Every window is made to measure from your property's specific dimensions. The finished result is indistinguishable from original period joinery.

  • Are timber casement windows suitable for conservation areas?

    Yes — timber casement windows are the preferred choice of planning authorities in London's conservation areas and for listed buildings. We are highly experienced in producing windows that meet heritage specifications. We can advise on any planning requirements during your free site survey.

  • Do your casement windows come with double glazing?

    Yes — all our casement windows are available with double or triple glazing as standard. We use slimline units where heritage appearance is required, which are accepted by most conservation authorities. All glazing meets current building regulations and significantly improves both thermal and acoustic performance.

  • How long does casement window installation take?

    A single casement window installation typically takes half a day to one full day. A full house of 6–8 windows is usually completed in 2–3 days. Bespoke manufacture lead times are typically 6–8 weeks from order confirmation — we'll confirm your specific lead time during the quotation process.

  • Do you offer a supply-only service?

    Yes — we can supply casement windows only, supply with a measure-up service, or supply and fit with full installation. We work closely with builders, architects, and directly with homeowners. Contact us to discuss which service best suits your project.

  • What areas of London do you cover?

    We cover all of Greater London. Based in North London (N7), we serve Islington, Hackney, Camden, Haringey, Kensington, Chelsea, and all London boroughs. Contact us to confirm coverage for your specific postcode.

Get In Touch

Request Your Free
Casement Window Survey

Whether it's one window or a full house — get in touch for honest advice and a free, no-obligation quote anywhere in London.

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Address

218 Hornsey Road, London, N7 7LL

Opening Hours

Monday – Friday8:00am – 4:30pm
Saturday8:00am – 3:30pm
SundayClosed

Send Us an Enquiry

Fill in the form and we'll get back to you within one business day — usually much sooner.

🔒 Your details are never shared. We'll only contact you about your enquiry.

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020 3488 1695 Email Us