Window Fitters | Commercial & Residential Window & Door 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.
Fixed trade day rates for pre-purchased frames. Dedicated CSCS glazier teams installing windows, bifolds, sliders, and curtain walling.
Book Labour-Only →Direct factory sourcing from leading UK fabricators at trade rates. Complete package including technical survey and 10-year guarantee.
Explore Supply & Fit →Full commercial fenestration packages for main contractors and developers. £5M Public Liability and £10M Employers Liability cover with site RAMS.
View Commercial Contracts →Reliable Window & Door Installation Subcontractors
Window Fitters Ltd provides specialist fenestration subcontracting across London and Surrey, installing client-supplied or trade frames to BS 8213-4 standards. Backed by £5M Public Liability and £10M Employers Liability cover, our directly employed CSCS glaziers deliver labour-only fitting at transparent day rates of £540 local and £580 extended.
As an established glazing company, our directly employed installers, window fitters, and door fitters deliver multi-unit residential window schedules, commercial curtain walling, and structural glass screens. Based in Croydon, we provide full installation services with transparent pricing in our installation cost guide, working strictly to site RAMS and project programmes.
Specialist Glazing Installation Services
Our directly employed CSCS glazing teams install high-performance window and door systems across Greater London and Surrey. Select a core service below to explore technical specifications and labour options.
Precision fitting of energy-efficient uPVC, aluminium, and timber casement windows for new builds, commercial developments, and residential replacements across London.
View Window Installation →
Specialist installation of multi-leaf aluminium bifold doors with slim sightlines, smooth running rollers, low thresholds, and certified thermal weather seals.
Explore Bifold Doors →
Secure exterior composite doors featuring solid timber cores, durable weatherproof skins, PAS 24 multi-point locking mechanisms, and precision hinge calibration.
View Composite Doors →
Large-span inline and lift-and-slide patio doors engineered with minimal profile sightlines, high load-bearing tracks, and thermal performance for panoramic views.
Explore Sliding Doors →
Full structural glass screens, curtain walling systems, and shopfront entrance assemblies installed under JCT subcontracts and rigorous site RAMS protocols.
View Commercial Glazing →
Traditional vertical sliding sash windows combining authentic heritage proportions, spiral balance or cord systems, double glazing, and compliant thermal insulation.
Explore Sash Windows →
Classic double-opening French patio doors fitted with 3D adjustable flag hinges, multi-point shootbolts, toughened safety glass, and low-profile access thresholds.
View French Doors →
Architectural Axorra aluminium front entrance doors with coplanar flush profiles, quad-glazed security glass, RC3 burglary protection, and superior thermal acoustic insulation.
View Entrance Doors →Why Window Fitters Ltd
Commercial main contractors, house builders, and property developers rely on our dedicated fenestration teams for accredited trade standards, direct workforce control, and guaranteed Building Regulations sign-off:
Dedicated full-time glazing operatives with verified CSCS accreditation, working strictly under CDM 2015 site RAMS with zero reliance on unvetted agency labour.
Direct coordination with Local Authority Building Control for Approved Documents L thermal ratings, Part F trickle ventilation, and Part Q security compliance certification.
Published fixed day rates of £540 local and £580 extended per 2-man team, offering predictable subcontract labour costs without inflated retail margins.
Backed by £5,000,000 Public Liability, £10,000,000 Employers Liability, Environment Agency waste carrier licence CBDL650268, and a 10-year installation guarantee.
How It Works
Our streamlined three-step engagement model provides main contractors and property owners with rapid pricing and guaranteed site installation:
Submit structural aperture dimensions, window schedules, architectural drawings, or site photos via our quote form or WhatsApp.
Receive a detailed commercial quotation breaking down labour day rates, fitting allowances, stage valuations, or complete trade supply costs within 24 hours.
Our directly employed CSCS glazier teams mobilise to site, complete installation to BS 8213-4 standards, and complete formal QA handover sign-off.
Recent Subcontractor Projects and Case Studies
Explore recent commercial and architectural glazing subcontracts delivered across Croydon, Greater 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 Facade Assembly (Central London)
Installation of architectural aluminium shopfronts and commercial entrance screens across an office redevelopment in central London.
Spec: Architectural Aluminium Commercial Entrances | PAS 24 SecurityRegional Coverage and Service Areas
Operating from our registered headquarters in Croydon, our mobile glazing units support residential and commercial projects across South London, Surrey, and Greater London. Explore our capital coverage in our London window fitters guide. We complete multi-unit installations and architectural builds in Bromley, Sutton, Mitcham, Purley, and across our South West London door installation corridor, including dedicated teams for Wandsworth, Wimbledon, Kingston, Richmond, and Surrey. 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 itemised quote.
Frequently Asked Questions for Commercial Clients & Main Contractors
Direct, factual answers to technical, commercial, and regulatory questions regarding trade glazier subcontracting, day rates, and Building Regulations compliance across London and Surrey.
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.
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 specialise in B2B JCT-governed glazing subcontracts. We operate with £5,000,000 Commercial Public Liability Insurance, £10,000,000 Employers Liability Insurance, full CDM 2015 site RAMS, direct LABC sign-off capability, and complete compliance with UK Building Regulations Documents L, F, K, Q, M, O, and B .
What is your payment policy for supply-and-fit orders compared to installation labour? +
For supply-and-fit contracts, custom-fabricated frame orders require 100% upfront settlement upon CAD approval and technical survey sign-off, passing factory trade savings directly to the client. Installation labour is invoiced separately in agreed commercial milestones or upon practical completion following QA inspection.
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 recognised 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 via Croydon HQ travel-time tiers (<15m local at £540/day, 15-45m extended at £580/day, >45m outer Surrey with half-day minimum), including Bromley, Sutton, Mitcham, Purley, and central London.
Author & Technical Reviewer: Marian Gheorghe
Head Installer & CEO, Window Fitters Ltd
Marian Gheorghe is the Active Director and Team Leader Installer at Window Fitters Ltd. With over 15 years of hands-on experience, he oversees technical safety and UK Building Regulations compliance for all residential and commercial glazing contracts.
Ready to discuss your project?
Window Fitters Ltd provides window and door installations across London and Surrey for residential, trade, and commercial projects.
Message our team on WhatsApp or send an enquiry with your drawings, photos, or measurements to receive a free, no-obligation quote.
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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."