Ventrolla Sash Window Specialists

Ventrolla is the UK's leading specialist in sash window restoration, heritage window restoration and timber window repair, helping architects, contractors and property professionals preserve historic buildings through expert conservation, retrofit and bespoke joinery solutions.

For more than 40 years, Ventrolla has been the UK's leading specialist in sash window restoration, heritage window restoration, timber window repair, listed building window refurbishment and conservation window upgrades. From our headquarters in Harrogate and nationwide network of specialist workshops, we help architects, conservation specialists, surveyors, contractors and property owners restore and enhance some of Britain's most important historic buildings.

Having restored, renovated or replaced more than one million timber windows, Ventrolla is recognised as one of the UK's foremost authorities in heritage window conservation and retrofit. Our expertise spans Grade I and Grade II listed buildings, country houses, schools, universities, hotels, public buildings, commercial heritage assets, royal residences and private period homes.

We believe that the best heritage windows are the original ones. Our approach prioritises repair, restoration and sympathetic retrofit wherever possible, preserving historic fabric while significantly improving thermal performance, weather protection, security, acoustic insulation and operational performance. Where replacement is necessary, our bespoke timber windows and doors are carefully designed to replicate original architectural detailing while meeting modern performance standards.

The UK's Heritage Window Experts

Ventrolla combines traditional craftsmanship with industry-leading engineering to deliver specialist heritage window solutions that respect the architectural integrity of every building.

Our services include:

• Sash window restoration
• Heritage window restoration
• Timber window repair
• Listed building window refurbishment
• Timber window conservation
• Heritage door restoration
• Timber window replacement
• Draught-proofing sash windows
• Secondary glazing solutions
• Heritage retrofit solutions
• Bespoke timber joinery
• Condition surveys and technical reports

Every project is carried out by highly skilled craftsmen using responsibly sourced timber alongside Ventrolla's award-winning proprietary systems, including the Ventrolla Perimeter Sealing System (VPSS) and Sash Removal System (SRS), developed to eliminate draughts, rattles and dust ingress while preserving original windows.

Trusted by Architects, Specifiers and Contractors

Ventrolla works in partnership with architects, conservation architects, surveyors, heritage consultants, principal contractors, local authorities and property professionals to deliver technically robust heritage window solutions across projects of every scale.

We understand the complexities of conservation projects, planning requirements and listed building consent. Our team provides specialist technical support from the earliest design stages, helping project teams develop compliant, practical and cost-effective restoration strategies.

Our commercial support includes:

• Detailed window condition surveys
• Technical specifications
• CAD section drawings
• NBS specification support
• Budget cost planning
• Tender assistance
• Listed building and conservation guidance
• Phased refurbishment programmes
• Dedicated commercial project management
• Site coordination and programme management

Whether delivering refurbishment programmes for heritage schools during holiday periods or carefully phased restoration works for occupied hotels, hospitals or public buildings, our experienced project managers ensure every project is delivered safely, efficiently, on programme and within budget.

Innovation Built on Heritage

Founded in 1983 by engineer Robert Tunnicliffe, Ventrolla pioneered one of the most significant innovations in heritage window restoration with the invention of the Ventrolla Perimeter Sealing System (VPSS) and Sash Removal System (SRS).

Originally developed to solve draught problems in traditional sash windows without replacing them, these award-winning systems remain central to our restoration approach today, helping preserve original timber windows while delivering modern levels of comfort and energy efficiency.

Over four decades later, innovation continues to sit alongside traditional craftsmanship, allowing Ventrolla to remain at the forefront of heritage window restoration throughout the UK.

Precision Heritage

Our philosophy is simple: preserve wherever possible, replace only when necessary.

Every project is delivered with the care, craftsmanship and technical expertise that has made Ventrolla one of the UK's most respected names in heritage window restoration. From cottages and manor houses to landmark public buildings and royal residences, our specialist teams help safeguard Britain's architectural heritage for future generations.

Our reputation is built on quality, technical excellence and customer satisfaction, reflected in our Excellent Trustpilot rating, industry awards including Property Business of the Year 2026, and the trust placed in us by architects, contractors, conservation professionals and homeowners alike.

Why Specify Ventrolla?

• Over 40 years specialising in heritage window restoration
• More than 1 million windows restored, renovated or replaced
• UK's leading sash window restoration specialists
• Nationwide network of specialist workshops and installation teams
• Award-winning proprietary restoration systems
• Responsibly sourced timber
• Dedicated commercial project management
• Technical design, CAD and NBS specification support
• RIBA-approved CPD seminars
• Specialists in listed buildings, conservation and heritage retrofit
• Trusted by architects, contractors, conservation officers and property professionals across the UK
• ConstructionLine Gold, CHAS, Safe Contractor accredited