Canons Ashby House, Northamptonshire

Canons Ashby House, a magnificent Grade I listed National Trust property in Northamptonshire, is a remarkable example of Elizabethan architecture, rich with centuries of history and cultural significance. As custodians of such an important heritage asset, the National Trust required a sensitive and specialist approach to restore the property’s original sash windows while safeguarding its historic fabric and treasured interiors.

Ventrolla, a market leader in heritage window restoration, was appointed to undertake the careful renovation of 16 original sash windows across the front elevation of the house, spanning both ground and first floors.

 

Project Scope: Challenges and Solutions

The project focused on conserving the original sash windows while subtly improving performance and longevity. Given the building’s Grade I listed status, every intervention had to respect strict conservation guidelines, prioritising repair over replacement and maintaining the historic character of the windows throughout.

Ventrolla’s heritage-led approach ensured the windows were restored in situ, with minimal disruption to visitors and no compromise to the building’s architectural integrity.

 

Craftsmanship and Conservation

The Ventrolla team employed traditional skills alongside specialist conservation techniques to extend the lifespan and functionality of the historic windows.

Timber Repairs and Sill Replacement
Decayed and rotten timber was carefully repaired or replaced using matching materials, preserving as much of the original fabric as possible while restoring structural integrity.

Re-glazing and Draught-Proofing
Windows were re-glazed where required, and discreet draught-proofing was installed to improve comfort and efficiency. To balance conservation needs, the Ventrolla Perimeter Sealing System (VPSS) was applied only to the sash perimeters rather than the full frames.

Hardware Retention
All original window hardware was retained and reused, ensuring the historic appearance and detailing of the windows remained unchanged.

Operational Improvements
The team upgraded the sash cords and reweighted the sashes, restoring smooth operation and full functionality to the windows.

Challenges and Solutions: Canons Ashby

Restoring windows within a historic house museum presented a unique set of challenges:

Protecting Sensitive Interiors
Canons Ashby contains delicate historic artefacts and finishes that require stable environmental conditions. A phased and methodical approach was adopted, with protective measures in place to prevent dust, debris, and fluctuations in temperature or humidity.

Minimal Disruption to Visitors
To maintain public access, Ventrolla used mobile access towers instead of fixed scaffolding, allowing restoration work to continue efficiently while preserving the visitor experience.

Strict Conservation Requirements
Working within the constraints of a Grade I listed building required careful decision-making. Limiting the VPSS application ensured improvements in comfort without altering the historic fabric or appearance of the windows.

The Importance of Heritage Preservation

At Canons Ashby, the original sash windows are an essential part of the house’s historic character and architectural significance. By restoring rather than replacing, Ventrolla helped retain the craftsmanship and materials that have endured for generations.

The completed works have enhanced visitor comfort, extended the lifespan of the original windows, and ensured their continued operation — all while respecting the conservation principles demanded by one of the UK’s most important heritage sites.

As Mark Flanagan, Managing Director of Ventrolla, explains:
“Working on a site as historically significant as Canons Ashby is an honour. Our aim was to retain the historic character of these beautiful sash windows while discreetly improving their performance and comfort.”

For more information on how Ventrolla can help preserve your heritage property, visit ventrolla.co.uk or call 0800 0277 454.