What Duration Windows does

Duration Windows, trading through its parent entity Quailfalcon Limited (sole director G. Chelton), is a UK trade manufacturer of premium aluminium windows and doors, founded in 1985 and operating from purpose-built facilities spanning over 68,000 sq ft across 18 specialised production units in Canvey Island, Essex. The company designs and fabricates made-to-measure aluminium fenestration products spanning five core families: Heritage windows and doors (steel-replacement systems including the slim 33mm Royale profile and 45° putty-line designs suitable for listed buildings and conservation areas), Modern windows and doors, Bifold doors (Durafold 1000, Premium HI, Continental Plus, Emperor Concealed, Heritage and Corner bifolds with U-values from 1.3 to 1.5 W/m²K), aluminium sliding patio doors, and secondary glazing. Core technology centres on polyamide thermal break aluminium profiles, complemented by proprietary features such as the Quick-Glaze Bead system, floating corner post for bifold doors, and patented concealed hinge mechanisms; product profiles are sourced through partnerships with Smarts Systems (the company's largest profile supplier) and ALUK.

The business operates a trade-focused B2B model, selling primarily to installers, builders, contractors, and trade account customers, with secondary consumer-direct sales through online estimators, an Essex showroom, and inbound enquiries. Pricing is quote-based and bespoke — written quotations are required, full payment is taken at order placement, and trade accounts operate under account terms and payment conditions. Nationwide delivery is handled through an in-house fleet from the Canvey Island facility, with an estimated 12-week lead time and a maintained database of experienced fitters for customer referrals. Certifications underpinning the value proposition include BFRC Window Energy Ratings, CE Marking, PAS 24:2012 enhanced security, and BS7950.

The company is privately held with no venture capital or private equity backing disclosed, is recognised as one of the UK's largest aluminium bifold manufacturers and the first UK manufacturer to sell aluminium bifolds to the trade, and has accumulated multiple industry awards across 2024-2025 including the NFA24 Aluminium Fabricator of the Year, BUILD Awards Best Aluminium Windows & Doors, and a 2025 Sustainability Award. All products carry a 10-year guarantee.

Name

Duration Windows

Legal name

Quailfalcon Limited

Website

https://duration.co.uk

Company type

Private

Founded year

1985

Operating status

Operating

Headcount range

11–50 employees

Short description

Duration Windows is a UK trade manufacturer of premium aluminium windows and doors, founded 1985, serving installers, builders, contractors, homeowners, and heritage/conservation property owners with made-to-measure products including bifolds, heritage steel-replacement systems, sliders, roofs, and secondary glazing.

Ownership category

akta.pro rank

Product category

Aluminium Windows and Doors Manufacturing

NAICS

Metal Window and Door Manufacturing (332321), Ornamental and Architectural Metal Products Manufacturing (33232)

SIC

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

akta.pro primary industry

Windows (IMADAIAC)

akta.pro secondary industries

Window Replacement (Residential) (HSAPAJAA), Custom Window & Door Fabrication & Replacement (HSAPAJAI), Window & Door Trim, Casing & Sill Replacement (HSAPAJAK)

Keywords

• Aluminium windows manufacturing
• Aluminium bifold doors
• Steel replacement windows
• Secondary glazing systems
• Trade window fabrication

Headquarters

HQ city

Canvey

HQ country

United Kingdom

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Operations, Personnel, Marketing or Sales, Technology or R&D

Revenue model

1. Aluminium Windows and Doors Sales: One-time product sales of bespoke made-to-measure aluminium windows, doors, bifolds, sliders, roofs, and secondary glazing. Products sold to trade customers (installers, builders, contractors) and consumers. Pricing quote-based with written quotation requests required.
2. Trade Account Sales: Trade customers purchasing products under account terms with payment conditions, manufacturing and supply agreements. Full payment required at time of order placement.

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels6 records

Core offering

Duration Windows is a UK trade manufacturer of bespoke made-to-measure aluminium windows, doors, bifold doors, sliding patio doors, aluminium roofs, secondary glazing, and heritage steel replacement systems. Products are fabricated at the company's 68,000+ sq ft facility in Canvey Island, Essex, using polyamide thermal break technology and supplied nationwide to trade customers (installers, builders, contractors) and direct consumers.

Product overview

Duration Windows is a UK-based trade manufacturer of premium aluminium windows and doors, operating since 1985. The product portfolio is organized around five core product families: Heritage Windows & Doors (steel replacement windows and doors with slim 33mm profiles, polyamide thermal break, suitable for listed buildings), Modern Windows & Doors (contemporary aluminium systems with slim sightlines and high security locking), Bifold Doors (multiple systems including Durafold 1000, Premium HI, Continental Plus with U-values from 1.3-1.5, Emperor Concealed with hidden hinges, Heritage Bifold, and Corner Bifold), Aluminium Sliding Patio Doors, and Secondary Glazing (horizontal sliders, vertical sliders, hinged, lift out, fixed and combination units for listed buildings and acoustic applications). Additional product lines include Aluminium Roofs (lantern roofs, skylights, conservatories, orangeries), Heritage Internal Screens (acoustic barriers for internal space division), Commercial Range (low-rise window walling), and Shaped/Curved Windows for specialist applications. The company offers extensive glass options including decorative, self-cleaning, solar control, and obscured glass, plus colour customization in over 200 RAL colours. All products are made-to-measure in the UK with a 10-year guarantee.

Differentiator

Problem solved

Functional benefit

Products and services

• Heritage Windows & Doors Aluminium steel replacement windows and doors designed to replicate traditional steel windows with slim sightlines and polyamide thermal break technology, suitable for listed buildings and conservation areas.
• Modern Windows & Doors Contemporary aluminium window and door systems featuring slim sightlines and high security locking mechanisms for modern residential applications.
• Vertical Sliding Windows (Smart 600) Aluminium vertical sliding windows providing easy operation and reliable performance with excellent natural ventilation capabilities.
• Durafold 1000 Bifold Door Great value bifolding doors with elegant contemporary looks, thermally efficient slim profiles, and wide range of colours including textured and dual colour options.
• Durafold 1000 Slimline Bifold Door Slim aluminium bifold door featuring Quick-Glaze Bead technology for quicker fabrication and installation, with U-values as low as 1.5 W/m²K.
• Premium HI Bifold Door High specification bifold capable of wide and tall panels up to 2750mm tall and 1200mm wide, achieving 1.4 Uw with double glazing and 1.2 Uw with triple glazing.
• Continental Plus Bifold Door Bifold door with 1.5 U-value thermal performance for double glazed and 1.3 for triple glazed units, supporting large panels up to 2600mm with slim interlocks of just 122mm.
• Emperor Concealed Hinge Bifold Door Bifold doors with concealed hinges fully concealed within the door leaf, providing a contemporary clean aesthetic and tested to PAS 24:2012 for enhanced security.
• Heritage Bifold Door Heritage style stepped sashes designed to replicate traditional steel look doors, with super slim 94mm meeting stiles and high security multi-point locking.
• Corner Bifold Door Full corner opening bifold doors with floating corner post, allowing two bifold doors to meet at a corner with the corner post sweeping away as doors open.
• Aluminium Sliding Patio Doors Sliding patio doors maximising glass area with slim aluminium profiles, offering wide panels and maximum natural light transmission.
• Luxury Door Plus Premium aluminium entrance doors with traditional Victorian, Georgian and Edwardian designs as well as contemporary styles, featuring high security locking systems.
• Elegant Aluminium Composite Door Modern collection of aluminium entrance doors combining elegance and style with outstanding performance for contemporary family homes.
• Aluminium Roofs Roof lantern, skylight and glazed roof systems including flush glass roofs, elegance skylights, lantern roofs, flat low roof lights, conservatories and orangeries.
• Conservatory Roof Bespoke aluminium conservatory roof styles from classic Victorian designs to contemporary garden rooms, with roof pitches between 5 and 45 degrees.
• Orangery Roof Aluminium orangery roof system providing additional living space with large windows and doors, styled as traditional conservatory roof or lantern roof.
• Secondary Glazing Purpose-made secondary glazing systems for listed buildings, acoustic applications and retrofit projects, including horizontal sliders, vertical sliders, hinged, lift out, fixed and combination units.
• Heritage Internal Screens Interior screening system for delineating residential and commercial spaces while providing effective acoustic barriers, with sleek elegant lines complementing window and door ranges.
• Commercial Range Low-rise window walling system structurally self-supporting for commercial entrance, frontage and glazing projects.
• Shaped Windows Curved on plan, shaped and curved aluminium windows and doors for specialist architectural applications.
• Royale Steel Replacement Windows Slimmest thermally broken aluminium windows at just 33mm deep, designed to replicate traditional steel windows with WER 'A' rating and BS7950 enhanced security certification.
• Heritage Stepped Steel Replacement Doors Slim-line thermally efficient aluminium doors replicating traditional steel doors with polyamide thermal break, suitable for single or double configurations.
• Room Dividers Internal sliding glass doors suitable for both commercial and domestic applications, made to the same quality as sliding patio doors with slim profiles and low threshold.
• Glazed Aluminium Doors Simple glazed doors available in single and double door configurations.

Quantifiable outcome

• Save around 10% on heating bills with secondary glazing
• +5 more outcomes

Named customers3 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

Feature4 records

Partnerships

Three partnerships are on record, tiered core.

• Smarts SystemscoreTechnology or IntegrationSmarts Systems approved fabricator. Duration Windows is described as the largest supplier of Smart products in the UK. Partnership involves using Smarts Systems aluminium profiles for window and door manufacturing.
• BFRC (British Fenestration Rating Council)coreTechnology or IntegrationBFRC certified. Products carry Window Energy Ratings (WER) certified under the BFRC Window Energy Rating Group Scheme, demonstrating compliance with energy performance standards.
• ALUK (Aluminium Systems)coreTechnology or IntegrationTrade supplier of ALUK products. ALUK is a leading supplier of aluminium profile systems used in Duration Windows' manufacturing.

Scale indicators6 records

Recent moves7 records

Expansion highlights4 records

Broad incumbents

• ALUK: UK aluminium systems brand supplying window, door and curtain wall profiles to fabricators and trade customers. Comparable in aluminium fenestration product set and UK market focus; existing partner of Duration Windows but also a broader incumbent.
• Technal UK: International aluminium systems brand operating in the UK with commercial and residential window, door and curtain wall solutions. Comparable in aluminium fenestration category but serves larger commercial projects than Duration Windows' residential-led business.
• Schüco UK: Global aluminium and steel systems provider with UK fabrication serving residential and commercial fenestration. Comparable aluminium window/door technology but operates at much larger scale and broader product portfolio than Duration Windows.
• Reynaers Aluminium UK: Global aluminium systems supplier with UK fabrication and distribution network offering window, door, sliding and curtain wall solutions. Comparable in aluminium fenestration scope but broader and upstream compared to Duration Windows' fabrication focus.

Direct peers

• IDSystems: UK manufacturer of bespoke aluminium windows, doors, sliding and bifold systems for residential and commercial projects. Comparable bespoke made-to-measure aluminium offering, heritage/architectural focus and trade-channel GTM.
• Origin Global: UK-based manufacturer of aluminium bifold doors, windows and sliding doors sold primarily through trade and direct channels. Closely comparable to Duration Windows in product mix (bifolds, sliders, windows), trade focus and UK-only domestic reach.
• Bereco: UK manufacturer of timber and timber-aluminium windows and doors targeting heritage, conservation and high-end residential markets. Comparable heritage/listed-building focus, made-to-measure model and trade supply channel to Duration Windows' Heritage range.
• Express Bifolds: UK specialist aluminium bifold door fabricator and supplier targeting trade fitters and consumers. Directly comparable to Duration Windows' bifold product family, made-to-measure model and trade pricing structure.
• Senior Architectural Systems: UK aluminium systems house designing and supplying window, door and curtain wall profiles to fabricators. Comparable aluminium fenestration portfolio and UK trade supply chain, though operating more upstream as a profile supplier than a fabricator.
• Folding Sliding Doors (FSD): UK specialist supplier of aluminium bifold and sliding doors to trade and consumer markets. Directly comparable bifold/slider focus, trade-friendly pricing and bespoke order model to Duration Windows.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/durationwindows
• YouTubeyoutube.com/user/DurationWindows
• Facebookfacebook.com/pages/Duration-Windows/221329171234244

Compliance3 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 Duration Windows