Steel Window Service and Supplies

What Steel Window Service and Supplies does

Steel Window Service and Supplies Ltd is a London-based specialist manufacturer, restorer, and installer of steel windows and doors, established in 1951. Operating from its Charlton headquarters with 11-50 staff and a directly employed UK installation network, the company produces in-house a portfolio of steel window systems including SMW, SMW+, W10, W20, W30, W40, W40-SBD (Secured by Design), and the W50TB thermally broken range, alongside fire-rated variants, internal steel screens, and comprehensive renovation and upgrade services for existing steel, cast iron, and bronze installations. In-house manufacturing capability includes hot-dip galvanising to BS EN ISO 1461 and polyester powder coating to BS 6497.

The company generates revenue through project-based contracts spanning new build and replacement, renovation, refurbishment, and upgrade services. Customer segments include commercial construction (primary), heritage and listed buildings (primary), residential/homeowners (primary), and public/institutional (secondary), with named clients across the BBC, Bovis Lend Lease, Sir Robert McAlpine, Skanska, Peter Jones, and St Paul's Cathedral Choir School. Pricing is custom and quote-based following free site visits, with each project assigned a personal project manager. The go-to-market is sales-led and consultative, engaging architects, main contractors, local authorities, housing associations, and property management companies through the website, phone, and direct outreach, with the company frequently serving as package contractor on major schemes.

The business is privately held with no disclosed funding rounds, no institutional investors, and is led by Managing Director Matthew Hahn. Certifications include Secured by Design (W40 range, BS 7950), BRE Green Guide B rating, BFRC Grade C Window Energy Rating (W30), and Steel Window Association membership. No AI/ML capabilities, app platforms, or geographic expansion beyond the UK domestic market have been disclosed, and no public revenue figures are available.

Name

Steel Window Service and Supplies

Legal name

Steel Windows Service & Supplies Ltd

Website

https://steelwindows.co.uk

Company type

Private

Founded year

1951

Operating status

Operating

Headcount range

11–50 employees

Short description

Steel Window Service and Supplies is a London-based specialist manufacturer, restorer, and installer of steel windows and doors, established in 1951. It serves commercial, residential, heritage, and public-sector clients across the UK via directly employed installation teams and project-based contracts.

Ownership category

akta.pro rank

Product category

Steel Windows and Doors

NAICS

Metal Window and Door Manufacturing (332321)

SIC

Metal Doors, Sash, Frames, Moldings & Trim (3442)

akta.pro primary industry

Windows (IMADAIAC)

Keywords

• Steel window manufacturing
• Steel window restoration
• Heritage window replacement
• Commercial window installation
• Fire rated windows

Headquarters

HQ city

London

HQ country

United Kingdom

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Supply Chain, Operations, Marketing or Sales, Infrastructure

Revenue model

1. New Steel Window and Door Sales: Design, supply and fix of new SMW, SMW+, W10, W20, W30, W40, W50TB and fire rated steel windows and doors for new build and replacement contracts.
2. Renovation and Refurbishment Services: Overhauling, servicing and upgrading of existing mild steel windows and doors. Includes off-site renovation at workshops, in-situ strip and redecorate, and full refurbishment services for heritage and listed buildings.
3. Project Management Services: Complete project management including surveying, estimating, CAD design, management and installation for both commercial and residential contracts.
4. Window Upgrade Services: Upgrading existing steel windows including security upgrades, heat loss improvements, draught-proofing, ironmongery upgrades, noise reduction, and double glazing retrofits.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels6 records

Core offering

Steel Window Service and Supplies manufactures, restores, and installs steel windows and doors for commercial and residential customers across the UK. Established in 1951 in London, the company produces a portfolio of product ranges (SMW, SMW+, W10, W20, W30, W40, W40-SBD, W50TB thermally broken, and fire-rated) in its own factory, with in-house hot-dip galvanising and polyester powder coating. It also delivers full project management from surveying and CAD design through to installation via its directly employed UK installation network.

Product overview

Steel Window Service and Supplies offers a comprehensive portfolio of steel windows and doors spanning multiple product ranges designed for heritage restoration, residential, commercial, and fire safety applications. The core product lines include SMW (the original 1920s standard metal window) for heritage and residential use; SMW+ for enhanced domestic replacement; W20 as the traditional heavy-duty commercial framing system; W30 as a slimline W20 derivative for domestic and light commercial applications; W40 as the most heavy-duty commercial range supporting thicker glazing; W40-SBD as the enhanced security variant achieving Secured by Design; and W50TB as the thermally broken range for contemporary architecture with superior energy efficiency. The company also offers Fire Rated Windows for the SMW, W20 and W40 ranges, Internal Steel Screens using W20 sections, and comprehensive Window Renovation and Upgrade Services. All products are manufactured in the company's London factory and are hot-dip galvanised and polyester powder coated for durability.

Differentiator

Problem solved

Functional benefit

Products and services

• SMW (Standard Metal Window) The original steel window range with small and profiled sightlines and unrivalled elegance, particularly suitable for residential and heritage applications, including replacement of pre-1948 SMW installations.
• W20 Windows Traditional heavy-duty framing system 32mm wide with 5mm thick flanges, accommodating single and insulating glass units up to 16mm. Suitable for internal, commercial, and heritage windows, and used as the natural replica replacement product for Universal Range windows.
• W30 Windows A slimline derivative of W20 suitable for outward opening double-glazed domestic and light commercial applications. Incorporates double weather seals plus fully drained and ventilated glazing; attained a Grade C Window Energy Rating under the British Fenestration Ratings Council scheme.
• W40 Windows Evolutionary development from W20 offering continuity of style with the same casement sightlines but with 40mm wide profiles that permit double or triple glazing up to 26.8mm thick. The most heavy-duty of the available mild steel window ranges; achieves Secured by Design standard.
• W40-SBD Enhanced security version of the W40 commercial grade hot rolled mild steel range, designed to satisfy the Secured by Design standard (BS 7950) for enhanced security.
• W50TB Thermally Broken Windows Energy efficient thermally broken steel windows with narrow sightlines and U-value as low as 1.4 W/m2K. Based on precision cold formed steel profiles of 1.5mm thickness with a high-density polyurethane isolator as thermal barrier. Accommodates double and triple glazing up to 37mm; ideal for contemporary architecture.
• Fire Rated Windows Steel framed glazed windows designed to protect life and property in the event of fire. Available for SMW, W20 and W40 ranges; examined by Warrington Fire Research to provide fire-resistant glazed fixed windows maintaining integrity for 30 or 60 minutes.
• Internal Steel Screens and Doors Bespoke internal steel doors and screens made from W20 sections, available in various styles and colours with multi-point locking or traditional mortice lock options. Used as stylish focal points for creating partitioned areas while maintaining openness.
• Window Renovation Services Overhauling, servicing and upgrading of existing steel, cast iron and bronze windows. Works include servicing, easing and adjusting opening frames, ironmongery replacement, broken glazing replacement, weather strip replacement, and frame member repair.
• Window Upgrades Upgrading existing steel windows through security enhancements, heat loss reduction, draught-proofing, ironmongery upgrades, noise reduction, and double glazing installation.

Quantifiable outcome

• U-values reduced from 5.7 W/m2K to 1.9 W/m2K with double glazing upgrades
• +4 more outcomes

Named customers10 records

Segments4 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Seven partnerships are on record, tiered core and flagship.

• Steel Window AssociationcoreStrategic or Co-development PartnerMember of the Steel Window Association which oversees the industry and ensures compliance with standards BS6510 (manufacturing) and BS6497 (powder coating). The association promotes products that have passed security tests and maintains codes of ethics among members.
• Architects and Design ProfessionalscoreImplementation/ SI/ Consulting PartnerWorks in partnership with architects, conservation officers and contractors involved in commercial projects. Early consultation from project inception helps avoid pitfalls and ensures smooth project execution. Provides CAD design services and technical expertise.
• Bovis Lend LeaseflagshipImplementation/ SI/ Consulting PartnerPackage contractor on major projects including 240 Regent Street and BBC buildings. Window package manager coordinates between architects, window manufacturer, and acoustic consultants.
• Sir Robert McAlpineflagshipImplementation/ SI/ Consulting PartnerSelected as package contractor/supply chain partner for Highbury Square East Stand project converting Arsenal stadium into residential apartments.
• Historic ScotlandcoreImplementation/ SI/ Consulting PartnerOversight body for Gribloch House project involving art deco residence designed by Sir Basil Spence. Ensures compliance with heritage conservation requirements.
• Simpson & Brown ArchitectscoreImplementation/ SI/ Consulting PartnerProject architects for Gribloch House who specified innovative Slimlite glazing units and brought Steel Window Service into the project.
• Arup Façade EngineeringcoreImplementation/ SI/ Consulting PartnerEngineering consultancy for St Paul's Cathedral Choir School project. Collaborated on window replacement specification and installation requirements.

Scale indicators11 records

Recent moves6 records

Expansion highlights4 records

Direct peers

• W20 Steel Windows: Specialist UK steel window manufacturer and installer with a product range focused on W20-style heritage sections. Competes directly for heritage replacement and commercial contracts with similar manufacturing and installation capabilities.
• Clement Windows Group: UK steel window manufacturer focused on heritage and conservation projects, with replica ranges similar to SMW and W20. Direct competitor in listed building and commercial heritage replacement work.
• Fendor High Performance Windows: UK-based manufacturer and installer of aluminium and steel windows, with comparable heritage and commercial project experience. Competes for spec-driven contracts where slim sightlines and modern performance are required.
• Crittall Windows: The most iconic UK manufacturer of steel windows, with deep heritage roots and a product range that overlaps directly with Steel Window Service's SMW and W-series offerings, including thermally broken and fire-rated options. Both serve heritage, commercial, and residential projects in the UK.
• Select Windows (Steel Window Specialists): UK manufacturer specialising in steel and aluminium windows for heritage and modern applications. Overlaps with Steel Window Service on commercial heritage and replica replacement projects.
• Real Steel (UK Steel Window Manufacturer): UK steel window fabricator and installer offering W20, W30, W40-style products. Direct peer in commercial and heritage replacement segments with similar UK distribution model.
• Shapland Ltd: UK-based specialist in steel window refurbishment, replacement, and new manufacture, serving commercial, residential, and heritage markets. Direct competitor for renovation and replacement contracts.

Broad incumbents

• Senior Architectural Systems: Larger UK aluminium and steel-look window systems supplier serving commercial and residential markets. Competes for commercial window packages where steel-look aesthetics are specified as a substitute for true steel.
• Schüco UK: Global fenestration systems supplier with a UK presence offering steel-look aluminium windows. Competes for the same commercial and high-end residential projects where slim sightlines and thermal performance are required, but at a different scale and cost base.
• Steel Window Association (Member firms): Industry body for UK steel window manufacturers, of which Steel Window Service is a member. Member firms collectively represent the UK steel window manufacturing industry, competing for heritage and commercial projects with overlapping product portfolios.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• Facebookfacebook.com/steelwindowsservices
• LinkedInlinkedin.com/company/steel-window-services

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Steel Window Service and Supplies