bars icon

Menu

close icon

Close

Close

Welcome to our website. Please read about what we do and don't be afraid to get in touch if you'd like to book.

@info@goldenratiojoinery.com | checkatrade

Get a quote

Call on: 02034881695 Or try: 07507391329

If you’d like a call back please send us a number to contact you

Restoring the Heritage of London’s Traditional Sash Windows

Our Google Business Profiles Golden Ratio Sash Windows & Doors Instagram Profile Force City & Guilds Fensa

Sash Window Repair, Restoration & Replacement in North London

Golden Ratio Windows: London's Premier Sash Window Specialists

Sash Window Replacements

Golden Ratio Windows combines traditional craftsmanship with modern thermal technology. We specialize in  Bespoke Sash Window Replacement in London for period homes, ensuring your property remains architecturally correct while benefiting from 21st-century energy efficiency.

Sash Window Repairs & Restorations

For properties where the original timber is still sound, we provide specialist Sash Window Restoration and heritage-grade Sash Window Repair. From fixing broken sash cords and rattles to full draught-proofing overhauls, we ensure your heritage windows function perfectly without the need for full replacement.

FENSA Registered Window Installers

Our FENSA-registered installers use precision-engineered Accoya® timber and slimline double glazing to provide high-performance installations across London's most prestigious conservation areas. We also specialise in Shop Front Installations for commercial properties.

Shop Front Installers

We also specialise in shop front installations in London, providing bespoke timber shop fronts for commercial properties.

So, whether you require specialist sash window restoration in London or are looking for dependable window installers for new builds in London, Golden Ratio Windows offers the expertise and service you can trust.

Specialist Sash Window Installation Across London

We provide heritage-grade window replacement and joinery throughout Greater London. Explore our work and sash window replacement services in all London Boroughs, including specialized heritage restoration in Islington and Hackney.

Technical Excellence & Heritage Materials

Window Engineering

Traditional box frames utilizing authentic weights & pulleys or modern spiral balances for seamless operation.

High-Performance Glass

Integrated Slimline vacuum glass and Acoustic (noise-reducing) glazing for modern thermal and sound efficiency.

Premium Timber

Sustainable Accoya® (acetylated wood), Sapele, and European Oak for maximum durability and finish.

Regulatory Compliance

FENSA Certified installations meeting Conservation Area and Grade II Listed building requirements.

London Business Solutions

Commercial Joinery & Fit-Outs

Beyond premium windows, we provide end-to-end bespoke joinery for London’s commercial sector—from iconic coffee houses to safety-compliant developments.

Coffee Bar Builders London

Coffee Bar Design & Build

Precision-engineered barista stations and artisan front-of-house counters. Built for workflow, durability, and aesthetic impact.

Explore Commercial Design →
Fire Door Installers London

Certified Fire Door Fitting

Life-safety compliance for London landlords and commercial premises. Certified FD30/FD60 installations with full ironmongery audit.

View Safety Standards →

Building Regulations Compliant • FSC Certified Materials • Master Craftsmen

London Heritage Sash Window Specifications

Master-grade restoration for London’s Grade II listed and Conservation Area properties.

RESIDENTIAL SPEC 01

Precision Components

Authentic box frames and meeting rails engineered for longevity. We utilize traditional lead weights and sash cords or modern spiral balances, tailored to your property’s structural requirements.

RESIDENTIAL SPEC 02

Advanced Thermal Performance

Integration of Slimline vacuum glass and Low-E coatings to achieve superior U-values without compromising the slim profile of traditional glazing bars.

RESIDENTIAL SPEC 03

Sustainable Timber

Specialists in Accoya® wood, European Oak, and Sapele. All timber is treated for maximum rot-resistance and paired with architectural hardware in brass, chrome, or satin finishes.

Conservation Compliance: Our work is meticulously designed to meet Article 4 Directions and Planning Authority criteria across all London Boroughs.

Why choose us?

We know that choosing the right company to complete work on your property can be difficult and time-consuming. Below we have highlighted some reasons to choose us for your next project.

  • Great Rates & Quotes

    Here at Golden Ratio Windows we strive to give all of our customers the best installation quotes we can, and constantly research our competitors so that we can keep doing so, time and time again. Are you looking for a sash windows and doors quote? Look no further!

  • A Name You Can Rely On

    We strive to be a window installation company that you can rely on. That’s why we arrive on time each day, and are well equipped for the job at hand. Doing so means that we can always stick to a predetermined time scale, and the initial quotation that we have provided.

  • A Time Served Team

    We are time served window and door installation company and have many years experience working within trade. Throughout our many years operating in London we have built up a wealth of experience along with a long list of satisfied customers.

  • Quality through and through

    Our work is of the highest quality due to our attention to detail and the fact we only use the highest qualtiy materials. We hand pick using only the most reliable and reputable suppliers. The time and care in which we put into picking our materials may seem unimportant, but these small touches result in a far superior finish that can stand the test of time.

  • Highly recommended

    Most of our work is gained through word-of-mouth recommendations, which goes to prove just how much care we put into our work. Many of our previous clients return to us for other work.

Here at Golden Ratio Windows we have built up an excellent reputation in our local area by offering the most comprehensive and expert service in London. From the planning stage to the finished article; we are with you every step of the way, making sure that whatever the task, you are completely satisfied with the end result. You can also rest assured that you will be receiving a professional, yet personal service for each job that we attend.

See our services

With so many years working in the trade, we are happy to answer any queries and provide quotes for any work that you are looking to have done. If you are in need of any work in London or the surrounding areas, then give us a call on 02034881695, or send us a message through our contact page.

Contact us

Expert Insights: Sash Window Installation in London

Can I install double glazing in a Grade II listed sash window?

Yes, in many cases. We specialize in "Slimline" vacuum glass and double-glazed units designed specifically to fit traditional thin glazing bars. This allows for modern thermal efficiency while maintaining the architecturally correct profile required by London planning authorities.

What are the benefits of Accoya® wood for London homes?

Accoya® is a high-performance acetylated timber that is virtually rot-proof and swell-resistant. For London sash windows, this means a lifespan of up to 50 years and significantly reduced maintenance compared to standard softwoods or hardwoods.

Do you handle Conservation Area planning permissions?

We provide full support for Article 4 Directions and Conservation Area compliance. Our windows are designed to be "Like-for-Like" replacements, ensuring that the heritage aesthetic of London’s period properties is preserved while meeting FENSA standards.

Navigating London’s Conservation Area Planning

Period properties in London require specialized expertise to meet the strict standards set by local Planning Authorities. Whether your home falls under the **Article 4 Directions** of the Islington Planning Council, the heritage preservation rules of Hackney Borough, or the conservation mandates in **Camden** and **Haringey**, we ensure every installation is compliant.

Islington & North

Specialists in Highbury, Finsbury Park, and Holloway conservation standards.

Hackney & East

Expertise in Dalston, Stoke Newington, and Hackney Central heritage projects.

Haringey & Muswell Hill

Compliance for Wood Green, Hornsey, and Tottenham architectural guidelines.

Central & West

Serving the City of London, Fulham, and Barnet with FENSA-certified joinery.