Window Fitters Ltd supplies and fits composite doors, bifold doors, sliding patio doors, French doors, and certified FD30/FD60 fire doors across London and Surrey. Every door installation is completed by directly employed, CSCS-carded door fitters with PAS 24 security compliance, £5,000,000 public liability insurance, and a 10-year frame guarantee.
Professional Door Installation by Experienced Door Fitters
Your exterior doors form the security perimeter and thermal boundary of your property. A poorly fitted door causes draughts, water ingress, and security weakness. Our experienced door fitters handle every stage of the door installation process: site measurement, structural lintel checks, frame positioning, mechanical fixing, perimeter sealing, lock alignment, and building control certification.
We provide two clear service options. Our Supply and Fit package covers sourcing, delivery, and fitting. Our Installation Only option provides skilled door fitters to install doorsets you have already purchased. Both options include full written guarantees and £5,000,000 insurance cover.
Composite Entrance Doors: High-Security Front Door Installation
We supply and install high-density foam and solid timber-core composite entrance doors built for maximum security and thermal performance. Composite doors use a GRP (glass-reinforced plastic) skin bonded to a rigid polyurethane foam core. This construction makes them 60% more thermally efficient than standard timber doors.
Composite door specifications:
- Door leaf thickness: 44mm to 70mm (depending on manufacturer and core material)
- Thermal performance: Ud values between 1.0 and 1.4 W/m²K (Document L compliant)
- Security: PAS 24 certified multi-point hook locking mechanisms with anti-snap, anti-bump, anti-drill euro-profile cylinders
- Hinges: Heavy-duty, flag-type adjustable hinges rated for doors up to 120kg
- Finishes: Over 30 GRP woodgrain and smooth colour options, including Anthracite Grey, Chartwell Green, and Schwarzbraun
Every composite door installation meets the PAS 24 security standard required by Document Q of the UK Building Regulations. The PAS 24 security standard tests doors against simulated break-in attempts including bodily force, lever attacks, and cylinder manipulation.
Bespoke Aluminium Entrance Doors
We also install bespoke aluminium entrance doors through our partnership with Axorra. Their made-to-measure range includes hinged, concealed-hinge, and pivot entrance doors with sidelights and toplights. We handle the full process from initial site survey and structural measurements through to final installation and building control sign-off.
Aluminium Bifold Door Systems
Our door installers fit thermally broken aluminium bifold door systems with ultra-slim sightlines. Bifold doors fold and stack neatly to one or both sides of the opening, creating a wide unobstructed connection between indoor living spaces and gardens or patios.
Bifold door specifications:
- Configurations: 2-panel to 7-panel systems, folding left, right, or split from centre
- Profile depth: 70mm aluminium with polyamide thermal break
- Track system: Stainless steel bottom-rolling tracks with brush pile draught excluders
- U-values: Whole-door Ud of 1.3 to 1.5 W/m²K (double-glazed) or 1.0 to 1.2 W/m²K (triple-glazed)
- Locking: Multi-point espagnolette locking with PAS 24 certification
- Maximum span: Up to 6 metres per opening without structural steel support
Read our detailed bifold door costs guide for London pricing breakdowns.
Sliding Patio Door Installation
Inline sliding patio doors offer large glass areas with smooth single-track operation. Unlike bifold doors, sliding doors do not fold outward, which makes them suitable for properties with limited external clearance such as balconies or narrow gardens.
- Materials: uPVC or thermally broken aluminium frames
- Glass: Double or triple-glazed Low-E units with Argon fill
- Operation: Easy-glide stainless steel rollers on aluminium tracks
- Security: Multi-point hook locks and anti-lift blocks meeting PAS 24 security standard
- Threshold: Standard or low-threshold options for Part M wheelchair accessibility
French Door Fitting
Our door fitters install classic French door configurations in uPVC and aluminium. French doors open outward or inward as a pair of fully glazed leaves. They suit traditional properties and provide a wider opening than a single entrance door. All French door installations include a centre-locking mullion, multi-point lock, and weatherproof compression seals.
Certified FD30 & FD60 Fire Door Installation
For blocks of flats, communal corridors, commercial offices, and schools, our qualified team installs certified FD30 and FD60 timber and composite fire doorsets. Every fire door installation follows BS 476-22 and BS EN 1634-1 testing standards.
Fire door components we install include:
- Intumescent strip seals: 15mm or 20mm strips in the frame rebate or door edge, expanding at 150°C to seal fire gaps
- Cold smoke seals: Neoprene or brush-type seals blocking toxic smoke spread before fire reaches the door
- Self-closing mechanisms: Overhead door closers tested to BS EN 1154, calibrated to latch shut from any angle
- Fire-rated vision panels: Pilkington Pyrodur or Pyrostop glazing with intumescent glazing beads
- Certified hinges: Grade 13 fire-rated steel butt hinges with intumescent pads
Fire door compliance falls under Document B (Fire Safety) of the UK Building Regulations. Read our full fire door compliance guide for detailed regulation breakdowns.
Low Threshold Doors & Part M Accessibility
We install weatherproof low-threshold doors meeting Approved Document M accessibility rules. Part M requires a maximum 15mm upstand at principal entrances for wheelchair and pushchair access. Our door fitters integrate subfloor levelling, slot-drainage channels, and compression weather seals to achieve a flush transition between internal floors and external decking or paving, whilst preventing water ingress.
UK Building Regulations & Door Compliance
| Building Regulation | Requirement | Our Standard |
|---|---|---|
| Document Q (Security) | All external doors must resist forced entry to PAS 24 | PAS 24 certified multi-point locking on every external door |
| Document L (Thermal) | Replacement doors: Ud ≤ 1.4 W/m²K | Composite doors achieve Ud 1.0 – 1.4 W/m²K |
| Document B (Fire Safety) | Fire doors in communal areas and flats | Certified FD30 and FD60 doorsets with intumescent seals |
| Document M (Access) | Maximum 15mm threshold upstand at principal entrances | Low-threshold integration with slot drainage |
| Document K (Safety Glass) | Safety glass within 1,500mm of door edge at floor level | BS EN 12150 toughened or BS EN 14449 laminated glass fitted |
Commercial Door Subcontracting & Direct Employment Guarantee
Main contractors and property developers choose Window Fitters Ltd for reliable site mobilisation. We guarantee 100% directly employed, CSCS-accredited door fitters with zero reliance on unvetted sub-contractors. We operate under standard JCT subcontract terms with full CDM 2015 RAMS.
Whether you need supply-and-fit packages or labour-only door installation teams, we provide fixed, itemised project quotes with dedicated site supervision.
Guarantees & Insurance
- 10-Year Structural Frame Guarantee
- 5-Year Sealed Glass Unit Guarantee
- 5-Year Workmanship Warranty
- £5,000,000 Public Liability Insurance
Full terms available on our guarantee page.
Frequently Asked Questions: Door Fitting & Installation
What types of doors do your door installers fit?
Our door fitters install composite entrance doors, uPVC patio doors, aluminium bifold and sliding doors, French doors, traditional timber doors, internal doors, and certified FD30/FD60 fire doorsets. Every door installation includes PAS 24 multi-point locking as standard.
Are your door installations PAS 24 security certified?
Yes. All external entrance doors and ground-floor patio doors are fitted with multi-point locking systems and anti-snap cylinders meeting the PAS 24 security standard. This satisfies Document Q of the UK Building Regulations for security in dwellings.
How long does a door installation take?
A standard composite front door installation takes 3 to 4 hours including removal of the old door, frame fitting, lock alignment, and sealing. A bifold door installation typically takes 1 full day for a 3 to 5 panel system. Fire door installations in communal areas take 2 to 3 hours per doorset.
Do you fit low-threshold doors for wheelchair access?
Yes. We install low-threshold door systems meeting Approved Document M. The maximum upstand is 15mm at principal entrances. We integrate subfloor levelling and slot-drainage channels to prevent water ingress while maintaining flush access.
Can you install fire doors in our block of flats?
Yes. We install FD30 and FD60 fire doorsets for flat entrance doors, communal corridors, stairwells, and plant rooms. Each fire door includes intumescent seals, cold smoke brushes, and a certified self-closing mechanism. We coordinate building control sign-off for compliance with Document B.
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.
Book a free site survey. No obligation, no pressure.
Window Fitters Ltd installs windows, doors, fire doors, and commercial glass facades across London and Surrey. Croydon head office, 40-mile service radius, 100% directly employed CSCS-carded fitters.
Our estimators respond within 24 business hours with a fixed-price quotation.
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."