Window & Door Fitting Company | Commercial & Residential Installers
Experienced window and door fitters for main contractors, property developers, and homeowners across London and Surrey. Supply and fit or labour-only glazier installation services.
Reliable Window & Door Installation Fitter
Window Fitters Ltd operates as a dedicated B2B glazing subcontractor and specialist installer of windows and doors for property developers, main contractors, and architectural builds across South London, Surrey, and Greater London. Based in Croydon, our directly employed fitting teams deliver multi-unit residential developments, commercial office fit-outs, and structural glass packages. We show up on schedule, work to your site RAMS, and get the job fitted right the first time.
We offer two primary contract structures to suit your site setup:
- Supply and Fit Packages: Direct sourcing of A-rated window and door units from our trusted suppliers at trade rates, including site surveys, safe offloading & floor distribution, and final sign-off. Learn more on our contracts page.
- Labour-Only Installation: Experienced glazier teams available for main clients who have already purchased architectural glass, aluminium curtain walling, or window systems (including Reynaers, Schueco, Velfac, and Norrsken), bifold, sliding, french or composite doors. Our teams handle safe floor distribution, mechanical positioning, fixing, and EPDM weather-sealing on site. Review details on our installation services page.
Every glazing package we install complies with UK Building Regulations. Our standard double-glazed systems comfortably achieve whole-window U-values (Uw) between 1.2 and 1.4 W/m²K, easily exceeding replacement thresholds and satisfying new build standards. For Passivhaus and ultra-low energy specifications, we supply and fit triple-glazed timber and alu-clad systems reaching whole-window U-values down to 0.64 W/m²K. We work directly with Local Authority Building Control (LABC) to arrange site inspections, submit technical drawings, and secure legal completion certificates. View compliance details on our legal documents and guarantee pages.
Core Service Pathways for Commercial & Architectural Projects
We structure our installation teams into three targeted pathways to serve commercial projects:
Commercial Contractors & Developers
Structured JCT subcontracts, structural curtain wall systems, certified FD30/FD60 fire door assemblies, and multi-unit window and door packages for new builds and commercial refurbishments.
Explore Commercial Contracts →Main Contractors (Materials Procured)
Specialist labour-only installation teams hiring for pre-purchased architectural glass, aluminium frames, shopfront screens, and high-performance window systems.
View Labour-Only Options →Architectural Residential Builds
High-end slimline bifold doors, structural glass wall panels, floor-to-ceiling sliding glass, composite entrance systems, and custom aluminium or uPVC profiles.
Explore Architectural Glass →Commercial Subcontracting Capabilities
Window Fitters Ltd bids on public and private commercial tenders across South London and Surrey. Our project management team prepares itemized tender returns based on architectural specifications, window schedules, and bills of quantities (BoQ).
Our fitters operate under standard JCT subcontract terms and strict site governance rules. We issue detailed Risk Assessments and Method Statements (RAMS) before getting on site, maintain dedicated site supervision, and ensure seamless progress alongside main contractor schedules. Explore our dedicated B2B contracting, fire door compliance, and curtain wall installation pages.
Directly Employed CSCS Glazing Operatives
Our workforce model relies entirely on directly employed, experienced glazing operatives. We do not use unvetted temporary sub-laborers. Every fitter on site holds a valid CSCS card, undergoes regular health and safety training, and operates strictly in compliance with CDM 2015 regulations.
This direct employment structure guarantees quality control, site cleanliness, and strict adherence to technical installation manuals. Read more on our window fitting team page and review current opportunities on our careers portal.
Why Partner with Window Fitters Ltd?
- Over a Decade of Glazing Experience: Specialist trade knowledge in multi-unit projects and commercial glass installations.
- 100% Directly Employed Workforce: Full accountability with zero reliance on unvetted third-party labor.
- Building Regulations Rigor: Direct alignment with Document L, Document F, Document K, and Document Q, supported by LABC certification.
- Comprehensive RAMS & CDM 2015 Safety: Site-specific risk assessments and method statements provided before getting on site. Read our safety measures.
- PAS 24 & Fire Security Standards: High-security multi-point locking, toughened safety glass, and certified FD30/FD60 fire door fitting.
- £5,000,000 Commercial Insurance: Comprehensive Public Liability Insurance protecting all commercial and multi-unit projects.
- Direct Trade Sourcing: Sourcing agreements with UK fabricators (Deceuninck, Liniar, Rehau, Profile 22, Schueco) passing trade cost savings to our clients.
Recent Subcontractor Projects & Case Studies
Explore recent commercial and architectural glazing contracts completed across Croydon, London, and Surrey:
24-Unit Apartment Glazing Package - Croydon
Supply and fit subcontract featuring high-performance acoustic uPVC windows and PAS 24 composite doorsets for a new residential development.
Spec: Document L 1.2 W/m²K | LABC Sign-OffStructural Glass & Curtain Wall - Surrey
Labour-only glazier subcontract for a high-end architectural residence featuring floor-to-ceiling glass panels and aluminium bifold systems.
Spec: Reynaers Aluminium | Structural GlazingCommercial Fire Door Assembly - London
Installation of certified FD60 fire door assemblies and fire-rated vision panels across an office redevelopment in central London.
Spec: FD60 Certified | BS 476 Compliance
About the Author: Marian Gheorghe
Head Window Fitter & Active Director, Window Fitters Ltd
Marian Gheorghe is the Head Window Fitter and Active Director of Window Fitters Ltd. With over 15 years of hands-on experience in the glazing industry across London, Marian leads our direct-employment fitting force and oversees technical compliance for all commercial subcontracts and high-end installs.
Regional Coverage & Service Areas
Operating from our base in Croydon, our mobile glazing units support all projects across South London, Surrey, and Greater London. We complete multi-unit installations and architectural builds in Bromley, Sutton, Mitcham, Purley, and surrounding areas. Review our full regional coverage on our location page.
Preparing a commercial tender or architectural specification? Review our case studies for technical references, explore our fitting process, or contact our Croydon commercial team for an itemized quotation.
Frequently Asked Questions for Commercial Clients & Main Contractors
Do you offer labour-only subcontract glazier fitting for pre-procured architectural glass systems? +
Yes. Window Fitters Ltd provides specialist labour-only glazier subcontracts for main contractors and developers who have procured windows, doors, or curtain walling directly from manufacturers. Our directly employed, CSCS-accredited teams handle safe unloading, positioning, mechanical fixing, and EPDM weather-sealing across London and Surrey. Visit our installation services page for operational details.
What U-values do your commercial window and door assemblies achieve under UK Building Regulations? +
Our standard double-glazed window packages deliver whole-window Uw values between 1.2 and 1.4 W/m²K, easily surpassing UK Building Regulations Document L replacement requirements (1.4 W/m²K) and meeting new build standards. For Passivhaus and ultra-low energy developments, our triple-glazed timber and alu-clad systems achieve whole-window Uw values ranging from 0.64 to 0.94 W/m²K.
Are you equipped to handle commercial JCT subcontracts and site safety compliance? +
Yes. We specialize in B2B JCT-governed glazing subcontracts. We operate with £5M Public Liability Insurance, full CDM 2015 site RAMS, direct LABC sign-off capability, and complete compliance with UK Building Regulations Documents L, F, K, Q, and B (FD30/FD60 fire doors). Learn more on our B2B contracting page.
Can you supply and install certified FD30 and FD60 fire doorsets for commercial redevelopments? +
Yes. We supply and fit certified FD30 and FD60 timber and composite fire door assemblies for multi-unit residential developments and commercial offices. Every installation complies with BS 476 / EN 1634 fire safety standards and PAS 24 security criteria. Explore details on our fire door installer page.
Are client choices limited to specific window brands or profile systems? +
No. We maintain market-wide sourcing flexibility. We source and fit systems from leading fabricators including Deceuninck, Liniar, Rehau, Profile 22, Schueco, Reynaers, and Velfac, focusing on structural durability, thermal rating, and architectural specification.
How do you handle Building Control certification and compliance sign-off? +
We coordinate directly with Local Authority Building Control (LABC) or approved inspection bodies. We manage the submission of technical drawings and glazing specifications, schedule site inspections, and secure official completion certificates for project records. Read our technical UK Building Regulations Guide and our building control inspections guide.
Is sticking aluminium foil on window glass a safe shortcut for thermal insulation? +
No. Taping aluminium foil or solar film onto window glass creates an impermeable moisture trap. Condensation pools inside frame rebates, creating ideal conditions for mould growth, which is a recognized allergen that can trigger respiratory symptoms. Additionally, solar heat absorption can degrade glass units and frame seals. Rather than temporary foil hacks, the safe and effective solution is upgrading to modern Low-E double glazing units. Read our trade guide on aluminium foil window shortcuts and health risks.
What areas do you cover for commercial subcontracting? +
From our Croydon headquarters, we support commercial developments across Greater London, Surrey, and surrounding areas within a 40-mile radius, including Bromley, Sutton, Mitcham, Purley, and central London. View our location page for full coverage details.
Contact us today to schedule a free survey.
We will work with you to choose the right door and window for your needs and budget, and then we will professionally install it.
Window Fitters Ltd is a specialist double glazing installation company serving London and Surrey since 2016. With our services, you can rest assured that you're getting the best value for your money.
We would be happy to discuss your needs and
provide you with free advice.
Our team will answer any questions you may have or help you choose the right installation service for your home or business.
Verified Google & MyBuilder Reviews
"Stunning Sash Windows in Croydon"
"Marian and his team replaced our old Victorian sash windows. They were clean, fast, and the double glazing has completely blocked out the street noise. Highly recommended!"
"Excellent Bifold Doors in Bromley"
"Installed beautiful grey aluminium bifold doors for our new kitchen extension. Smooth gliding mechanism and great insulation. The best quote we got in Kent."
"Perfect Front Door Upgrade in Sutton"
"Very happy with our new composite door installation. Excellent lock security and high-quality GRP slab finish. Fast half-day fitting and no mess left behind."