What Rationel Windows does

Rationel Windows (legal entity DOVISTA UK Ltd.) is a UK-based bespoke manufacturer of timber and aluminium-clad timber windows and doors, founded in 1954 and headquartered in Huntingdon. The company serves UK homeowners, self-builders, renovation contractors, and new-build developers, combining Scandinavian design heritage with UK-market specifications. Its product range is organised into two families — AURA and AURAPLUS (contemporary styling) and FORMA and FORMAPLUS (traditional styling) — spanning seven window types and six door types, with 200+ RAL colour options and multiple glazing configurations including triple-glazed units. Manufacturing is made-to-order, with each project specified to bespoke dimensions, finishes and performance criteria.

The product offering is backed by a layered certification stack: FSC-certified timber, CO2-neutral certification, Indoor Climate Label, Secured by Design (police-preferred specification) accreditation, UKCA marking (achieved January 2023), and CE marking. Technical emphasis is placed on thermal efficiency, acoustic performance, security and design flexibility, positioning the range for both refurbishment and new-build applications. Recent product extensions include AURAPLUS Sliding Patio Doors and the Rationel ID handle range.

Rationel Windows operates a B2B2C model, selling exclusively through a network of approved UK distributors rather than directly to end consumers. Pricing is bespoke per project specification. The company is a wholly owned subsidiary of DOVISTA Group, which is in turn owned by VKR Holding (the Danish parent behind the VELUX brand). UK operations are being consolidated under the VELFAC UK brand, with the rebrand scheduled for completion by the end of September 2026. The company is privately held and does not publicly disclose revenue; stated headcount is in the 11–50 range.

Name

Rationel Windows

Legal name

DOVISTA UK Ltd.

Website

https://rationel.co.uk

Company type

Private

Founded year

1954

Operating status

Operating

Headcount range

11–50 employees

Short description

Rationel Windows is a UK-based bespoke manufacturer of Scandinavian-designed timber and aluminium-clad timber windows and doors, serving homeowners, self-builders, and developers through an approved UK distributor network under DOVISTA Group (VKR Holding).

Ownership category

akta.pro rank

Product category

Windows and Doors Manufacturing

NAICS

Wood Window and Door Manufacturing (321911), Custom Architectural Woodwork and Millwork Manufacturing (337212)

SIC

Millwood, Veneer, Plywood, & Structural Wood Members (2430)

akta.pro primary industry

Doors, Windows & Millwork Retail (Interior/Exterior Doors, Windows, Moulding) (CRAIAEAI)

Keywords

• Timber window manufacturing
• Aluminium-clad windows
• Bespoke door manufacturing
• Energy efficient glazing
• Scandinavian window design

Headquarters

HQ city

Huntingdon

HQ country

United Kingdom

HQ region

Europe

Offices1 record

Markets served

GTM type

B2C

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Windows and doors sales: Bespoke timber and aluminium-clad timber windows and doors sold through a network of approved UK distributors. Products are manufactured to order based on customer specifications including size, colour, glazing type, and opening function.
2. Professional services: Distributors provide additional services including site visits, quotes, product advice, delivery, and optional installation services.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels8 records

Core offering

Rationel Windows manufactures and supplies bespoke timber and aluminium-clad timber windows and doors for the UK residential market through two design ranges: AURA/AURAPLUS (contemporary Scandinavian style) and FORMA/FORMAPLUS (traditional British style). All products are made to customer specification with over 200 colour options, multiple glazing types, and various opening configurations, sold through a network of approved UK distributors who provide quotes, site visits, delivery, and optional installation.

Product overview

Rationel Windows is a bespoke windows and doors manufacturer offering Scandinavian-designed timber and aluminium-clad timber products through two main product ranges: AURA/AURAPLUS (contemporary) and FORMA/FORMAPLUS (traditional). The portfolio includes seven window types (fixed light, top guided, side hung, side guided, fully reversible, tilt and turn, and shaped) and six door types (flush entrance, glazed entrance, patio, tilt and turn, casement, and sliding patio). All products are made to order with extensive customization options including over 200 RAL colours, multiple glazing types (OBSCURE, SOUND, SOLAR, SECURE, FACADE, SAFETY), and various hardware options. The company operates through a distributor network across the UK and is part of the DOVISTA Group owned by VKR Holding.

Differentiator

Problem solved

Functional benefit

Brands

• Rationel AURA: Contemporary timber window range with clean lines and minimalist design, suitable for modern construction and Scandinavian feel.
• Rationel AURAPLUS
• Rationel FORMA
• Rationel FORMAPLUS

Products and services

• Rationel AURA timber windows Contemporary timber window range with clean lines and minimalist Scandinavian design, available in double or triple glazing, suitable for modern construction and low-energy or Passive House projects. AURA triple glazed achieves 0.78 W/m² K U-value and 42 dB Rw sound reduction.
• Rationel AURAPLUS aluminium-clad timber windows Contemporary aluminium-clad timber window range with sleek flat frames and clean lines. External aluminium cladding extends product lifetime by over 20 years and provides minimal maintenance. AURAPLUS triple glazed achieves 0.79 W/m² K U-value.
• Rationel FORMA timber windows Traditional timber window range with angled glazing bead and ovolo moulded profile, ideal for country-style and traditional British architecture. Available in double or triple glazing with energy-efficient performance.
• Rationel FORMAPLUS aluminium-clad timber windows Traditional aluminium-clad timber window range with soft lines and bevelled edges, complementing traditional British architecture. Natural wood interior with low-maintenance aluminium cladding exterior, available in dual colours at no extra charge.
• Fixed Light Windows Non-opening windows with the largest possible glass area for maximised daylight and views. Glass is inserted directly into the frame, suitable for areas where ventilation is not required.
• Top Guided Windows Windows where the top of the sash slides downwards and the bottom opens outwards, controlled by tracks and slides, with no visible external hinges.
• Side Hung Windows Outward opening windows with visible hinge on right or left side and friction brake allowing the window to be fixed in any open position.
• Side Guided Windows Windows controlled by tracks and slides with no visible external hinges. The adjustable sash moves towards the middle when opened, ideal for multi-storey buildings.
• Fully Reversible Windows Outward opening windows where the sash can be rotated up to 180 degrees on a horizontal axis, allowing easy cleaning of the external glass surface and optimum ventilation.
• Tilt and Turn Windows Versatile inward opening windows with two functions: tilt opens the top of the sash for ventilation, while turn allows inward opening hinged from the side for full access.
• Shaped Windows Custom window shapes including circular, curved (arched), triangular, and bespoke designs to match any stylistic ambition, manufactured to order.
• Flush Entrance Doors Side-hinged entrance doors available inward or outward opening with visible and adjustable grey Dacromet hinges, fitted with a three-point espagnolette locking system.
• Glazed Entrance Doors Entrance doors constructed using frame and sash with options for glazing bars, transoms and mullions. Hung on grey Dacromet adjustable hinges with three-point locking.
• Patio Doors Doors designed to connect indoor and outdoor space, available as inward or outward opening, ideal for easy access to balconies, gardens and patios.
• Tilt and Turn Doors Inward-opening doors with two functions: hinged from the side for opening, or tilted for ventilation. Features large glass area for maximum light intake.
• Casement Doors Outward opening doors providing access to balconies, gardens and patios with slim construction allowing maximum daylight and heat into the home.
• Sliding Patio Doors Sliding doors designed to lift and glide easily, suitable for spaces where swing area is limited. Available in AURAPLUS triple-glazed configuration.

Quantifiable outcome

• AURA triple glazed achieves 0.78 W/m2 K U-value
• +6 more outcomes

Named customers6 records

Segments3 records

Ideal customer profiles1 record

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

Two partnerships are on record, tiered core.

• VELFAC UKcoreOthers · 1 September 2026Rationel products are being rebranded under the VELFAC UK brand from end of September 2026. Rationel Aura and Auraplus become VELFAC Ribo; Rationel Forma and Formaplus become VELFAC Classic. Products continue as part of the VELFAC range.
• DOVISTA GroupcoreOthersRationel is part of the DOVISTA Group, which comprises a number of Europe's leading window and door companies. DOVISTA is owned by VKR Holding and strives to bring air and light into people's lives.

Scale indicators4 records

Recent moves5 records

Expansion highlights5 records

Broad incumbents

• VELUX Group: VELUX is the global leader in roof windows and skylights and is also owned by VKR Holding, Rationel's ultimate parent. It competes in adjacent window categories for daylight-focused residential projects and shares the Scandinavian design heritage, making it a broad incumbent peer within the same corporate family.
• Andersen Windows & Doors: Andersen is one of the largest North American window and door manufacturers with a growing international presence, offering timber, composite, and aluminium-clad product lines. It parallels Rationel's premium timber-window positioning and bespoke customisation, though it operates as a much broader incumbent globally.
• Schüco: Schüco is a major European systems provider for windows, doors, and façades, primarily serving commercial and high-end residential projects. It overlaps with Rationel in the premium aluminium-clad window and door category, though Schüco operates as a broader incumbent across many product lines and geographies.

Direct peers

• Reynaers Aluminium: Reynaers is a European manufacturer of aluminium and aluminium-clad window, door, and curtain-wall systems for residential and commercial projects. It competes with Rationel's aluminium-clad AURAPLUS and FORMAPLUS lines in the premium residential and developer market across the UK.
• VELFAC: VELFAC is the sister brand under DOVISTA Group that will absorb the Rationel product range from September 2026. It produces aluminium-clad timber windows and doors for the UK and European markets, overlapping directly with Rationel's AURAPLUS and FORMAPLUS lines in materials, design philosophy, and customer segments.
• Marvin Windows and Doors: Marvin is a US-based manufacturer of made-to-order timber, timber-aluminium clad, and Ultrex windows for premium residential and architectural projects. It is closely comparable to Rationel in product strategy (bespoke timber, high thermal/acoustic performance, design-led differentiation) though it primarily serves the North American market.
• Bereco: Bereco is a UK-based manufacturer of high-performance timber and timber-aluminium composite windows and doors, selling through a national installer network. It is one of Rationel's closest direct competitors in the bespoke UK timber window segment for self-build, renovation, and developer projects.
• Idealcombi (Denmark): Idealcombi is a Danish manufacturer of timber and timber-aluminium composite windows and doors with deep roots in Scandinavian design, directly mirroring Rationel's heritage. It competes in the same premium, energy-efficient window segment across Northern Europe, including Denmark and the UK.
• Internorm: Internorm is a leading European manufacturer of timber, timber-aluminium, and uPVC windows and doors, headquartered in Austria. It directly competes with Rationel in the premium bespoke European window segment, serving self-builders, developers, and renovation projects across the UK and Ireland with similar thermal and security performance claims.

Regional players

• Fakro: Fakro is a Polish-headquartered manufacturer of roof windows, loft ladders, and related building products with strong UK distribution. It overlaps with Rationel's daylight-focused window proposition but concentrates on roof windows rather than the wall-window and door categories where Rationel primarily competes.

Market position

Strengths4 records

Weaknesses2 records

Competitive moat4 records

Key risks4 records

Key highlights6 records

Customer concentration

• Xx.com/Rationel_UK
• Facebookfacebook.com/rationelwindows
• Pinterestpinterest.dk/rationelukltd/doors

Compliance6 records

Revenue estimate

Valuation estimate

Number of profiles

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 Rationel Windows