What Masterframe Windows does

Masterframe Windows is a UK-based, employee-owned manufacturer of PVC-U sliding sash windows designed to replicate the appearance of traditional timber joinery. Founded in 1988 (incorporated 1994) and headquartered at a single manufacturing site in Witham, Essex, the company specialises exclusively in vertical sliding sash windows, deliberately avoiding casements, doors, and patio products. Its core product portfolio spans the premium Bygone Collection (Symphony, Harmony, and Melody tiers), the Vintage and Heritage Collections for trade and commercial projects, and the Classic Collection for open trade purchase. Differentiated technology centres on the patented Timberweld® butt-jointed corner process, a 39mm GRP slim meeting rail, and a strategic partnership with AGC Glass Europe to offer FINEO vacuum insulating glass achieving U-values as low as 1.2.

The company operates a two-tier distribution model. The premium Bygone Collection is sold exclusively through a vetted, UK-wide network of approved Bygone Master Installers selected for workmanship quality, local reputation, and financial standing, while Classic, Vintage, and Heritage ranges are available for direct trade and commercial purchase. Masterframe holds a dense stack of industry accreditations, including BBA 'Whole of Life' certification, ISO 9001:2015, ISO 45001, Secured by Design (PAS 24), BFRC A-rating, Energy Savings Trust recommendation, CE marking, and VEKA Approved Fabricator status, and is a long-standing member of the Glass and Glazing Federation. Customers include period property homeowners, luxury housing developers (David Ashley Developments, Ravenworth, Firwood Hall Estate), education and public sector clients (Guildford High School, Sandfield Primary School, London Borough of Barking and Dagenham), social housing providers (Southern Housing Group), and heritage hospitality venues (Royal Troon Golf Club).

Revenue is generated primarily through hardware sales of manufactured windows, with pricing conducted on a quote basis routed to Master Installers or directly to trade partners, and backed by 12-year and 10-year guarantees on the Bygone and Classic collections respectively. Marketing is delivered through content (virtual showroom, Price Master designer, case studies, brochures), event participation at homebuilding shows, and the installer network itself, which functions as a referral and lead-conversion channel. The company remains privately held, founder-led under Managing Director Carol Slade, with no external funding raised and a headcount of 51-100 employees.

Name

Masterframe Windows

Legal name

Masterframe Windows Ltd

Website

https://masterframe.co.uk

Company type

Private

Founded year

1994

Operating status

Operating

Headcount range

51–100 employees

Short description

Masterframe Windows is a UK-based, employee-owned manufacturer of PVC-U sliding sash windows that replicate traditional timber joinery, serving period property homeowners, luxury developers, public sector clients, and social housing providers exclusively through a vetted Master Installer network and direct trade sales.

Ownership category

akta.pro rank

Product category

PVC-U Sash Window Manufacturing

akta.pro primary industry

Windows (IMADAIAC)

akta.pro secondary industries

Window & Door Frame/Sash Replacement (HSAPAJAF), Custom Window & Door Fabrication & Replacement (HSAPAJAI)

Keywords

• PVC-U sash windows
• Timber-alternative windows
• Sliding sash windows
• Heritage window manufacturing
• Window fabricator UK

Headquarters

HQ city

Witham

HQ country

United Kingdom

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Bygone Collection Sales: Premium PVC-U sash windows sold exclusively through approved Master Installers. The Bygone Collection includes Symphony (flagship), Harmony (versatile), and Melody (value) ranges. Revenue is generated through the installer network who purchase windows and resell with installation.
2. Classic/Vintage Collection Trade Sales: Standard trade PVC sash windows available for anyone to purchase, including commercial projects. Sold directly to trade partners and contractors without installer restrictions.
3. Heritage Collection Sales: Heritage Collection windows targeting commercial and luxury residential developments with chamfered sash profiles.

Pricing tiers

Go-to-market motion3 records

Distribution channels3 records

Marketing channels8 records

Core offering

Masterframe Windows manufactures PVC-U sliding sash windows designed to replicate the appearance of traditional timber sash windows. Its product portfolio spans the premium Bygone Collection (Symphony, Harmony, Melody), the Heritage and Vintage Collections for trade and luxury projects, and the standard Classic Collection. The premium Bygone range is sold exclusively through a vetted network of approved Master Installers across the UK, with standard trade products available to commercial buyers.

Product overview

Masterframe Windows specializes exclusively in UPVC sliding sash windows, offering multiple product lines targeting different market segments. The flagship Bygone Collection comprises three tiers: Symphony (premium), Harmony (versatile with customization options), and Melody (value). The Vintage and Heritage Collections serve trade and commercial projects. All products feature patented Timberweld technology for authentic timber-like butt joints. Optional FINEO vacuum insulating glass provides advanced thermal performance. The company operates through an approved Master Installer network for the Bygone products, with standard trade products available to all.

Differentiator

Problem solved

Functional benefit

Brands

• Bygone Collection: Flagship range of premium timber-alternative sash windows including Symphony, Harmony, and Melody product lines
• Bygone Symphony
• Bygone Harmony
• Bygone Melody
• Heritage Collection
• Vintage Collection
• Classic Collection
• London Sash & Frame

Products and services

• Bygone Symphony Premier tier of the Bygone Collection; PVC-U sash window with Timberweld butt-jointed corners, 39mm GRP meeting rail, run-through horns, deep bottom rails, and optional FINEO vacuum insulating glass (U-value 1.2). Sold exclusively through approved Bygone Master Installers. Aimed at period property owners and conservation-area projects where the timber look is critical.
• Bygone Harmony Versatile mid-tier of the Bygone Collection with numerous optional extras for individual customization. Features authentic period detailing including deep bottom rails and continuous run-through horns, energy-efficient glazing, and Timberweld technology. Sold exclusively through approved Master Installers.
• Bygone Melody Value tier of the Bygone Collection sharing the same frame and sash profiles as Symphony and Harmony. Provides an authentic timber-alternative sash window at a more accessible price point. Sold exclusively through approved Master Installers.
• Vintage Collection Premium PVC-U sash windows with authentic chamfered sashes, heavy-duty Torso II balances, and robust cam catches. Designed for clients who appreciate authentic detailing with maximum security and reliability. Sold via trade/commercial channels, as demonstrated by large orders including 280 windows for The Moorings development and projects for schools and council buildings.
• Heritage Collection Engineered to combine classic design with modern high performance using chamfered sashes. Features slim 39mm meeting rail, staff bead detail, continuous horns, and deep bottom rail for traditional aesthetics. Sold via trade/commercial channels; evidenced by 120+ Heritage Collection windows supplied to The Spinney luxury development in Pebble Grey RAL 7032.
• Classic Collection Standard trade PVC-U sash windows available for anyone to purchase, as opposed to the Bygone Collection which requires Master Installer fitting. Backed by a 10-year guarantee and Masterframe's standard BBA, ISO 9001, and Secured by Design certifications.
• London Sash and Frame System Unique sash window system for replacing timber windows with an arched exterior and square interior, commonly found in Victorian buildings. Features sculpted curved trim for a seamless fit. Evidenced by use at Guildford High School's Victorian school building and other period renovation projects.

Quantifiable outcome

• BBA approved lifecycle in excess of 30 years
• +5 more outcomes

Named customers11 records

Segments5 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature8 records

Partnerships

Seven partnerships are on record, tiered core.

• AGC Glass Europe (FINEO)coreStrategic or Co-development Partner · 1 January 2021Strategic partnership between AGC Glass Europe and Masterframe to bring FINEO vacuum insulating glazing for PVC-U sash windows to the UK market. FINEO provides exceptional thermal insulation with U-values as low as 1.2, combining the appearance of single glazing with modern performance benefits.
• VEKA UK Group (Halo Profile)coreTechnology or IntegrationMasterframe is a VEKA Approved Fabricator using Halo profile - a brand of the market leading VEKA UK Group. Achieved by audit on over 70 different factors regarding manufacturing systems and skills. Demonstrates production to high standards demanded by the industry's leading systems company.
• Glass and Glazing Federation (GGF)coreStrategic or Co-development PartnerMasterframe has been GGF member since the mid-90s. The MD has served on the GGF main board and chaired the Home Improvement Executive, FENSA, and BFRC. GGF only accepts financially secure companies and verifies through premises visits and account checks.
• British Board of Agrément (BBA)coreStrategic or Co-development PartnerMasterframe is one of the very few vertical slider manufacturers to have achieved BBA 'Whole of Life' performance tested status for all sash windows produced. BBA is the UK's major authority offering approval and certification services.
• Secured by Design (SBD)coreStrategic or Co-development PartnerMasterframe assists BSI in formalising the standards to which all sash windows should apply. All products meet PAS 24 security standards and carry Secured by Design approval.
• British Standards Institution (BSI)coreStrategic or Co-development PartnerMasterframe holds ISO 9001:2015 certification through BSI/URS audits. Company assisted BSI in formalising sash window standards (PAS 24).
• Bygone Master Installer NetworkcoreChannel Partner/ Reseller/ DistributorNetwork of specially trained and vetted installers who exclusively sell and install Bygone Collection products. Installers are selected based on quality of workmanship, local reputation, working relationship, and financial position. The network covers the UK and is integral to Masterframe's distribution strategy.

Scale indicators4 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Quickslide: UK manufacturer of uPVC vertical sliding sash windows with both trade and installer-supplied distribution, directly competing with Masterframe across Classic, Vintage and Heritage-equivalent tiers.
• Roseview Windows: UK specialist manufacturer of uPVC vertical sliding sash windows selling under the 'Ultimate Rose' brand with a similarly premium, conservation-focused positioning, making it the closest direct competitor to Masterframe's Bygone Collection.
• Dempsey Dyer: UK manufacturer with a dedicated vertical slider sash window range, providing another overlapping specialist alternative for installers and developers specifying period-appropriate fenestration.
• Victorian Sliders: Direct UK competitor manufacturing PVC-U vertical sliding sash windows aimed at the period-property and conservation-area replacement market, with comparable Heritage/Charcoal ranges overlapping Masterframe's Classic and Vintage lines.
• Zenith Staylock: UK-based vertical slider sash window fabricator competing head-on with Masterframe in the trade and commercial replacement segment, with comparable VEKA/Halo platform heritage.

Others

• VEKA UK Group: Systems supplier of the Halo profile Masterframe fabricates from, and broader fenestration platform whose other approved fabricators compete for the same trade and installer customers downstream.
• AGC Glass Europe (FINEO): Glazing innovation partner enabling Masterframe's 1.2 U-value offering, whose vacuum glass platform is increasingly referenced by competing sash fabricators seeking comparable thermal performance.

Broad incumbents

• Safestyle UK: Large UK uPVC window and door retailer/installer addressing similar end-customers with a much broader product range, providing indirect competitive pressure on Masterframe's installer-channel volumes and consumer pricing.
• Anglian Home Improvements: National UK home improvement incumbent offering windows alongside doors, conservatories and roofing, serving some of the same period-property homeowner segment as Masterframe but at much broader scale.
• Everest Limited: Established UK home improvements brand selling windows, doors and conservatories directly to homeowners, competing in the same replacement-fenestration wallet but with a portfolio approach versus Masterframe's sash-only focus.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks7 records

Key highlights7 records

Customer concentration

• Xx.com/masterframesash
• Facebookfacebook.com/masterframe.windows
• LinkedInlinkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.masterframe.co.uk%2F&title=Masterframe&source=Masterframe

Compliance10 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles6 records

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 Masterframe Windows