Bow fronted French doors on Listed building

French doors are often a classic and key feature of many listed buildings and conservation properties – and need sensitive restoration work to repair and replace them without jeopardising the original architecture.

At Timbawood we have worked on several Grade II listed properties that have needed repair work on their French doors. One of these is the White House (below), which overlooks the River Thames at Isleworth in London, which required a complex mixture of restoration, part replacement and full replacement of the French doors and sash windows.

Grade II listed restoration project in Isleworth, London

Our client, a developer of high-end residential apartments and homes, wanted to improve the noise insulation of the windows and doors, being under Heathrow Airport’s flight path, while maintaining the original architectural integrity of the property.

We refurbished the unique bow fronted French doors, which included new full perimeter draught proofing, and deglazing and reglazing the doors with single glazed restoration, laminated glass.

Restoration glass refers to glass that is made to have the authentic uneven surface of original heritage (crown) glass, rather than the modern flat look. The glass is also laminated not only to give more security, but also to improve thermal and acoustic insulation as it has a soft plastic ‘interlayer’ through the centre which is a poor conductor of sound and heat.

We also used putty rather than timber beads to fix the glass in place, which would have been how the doors were originally made.

Other French doors on the property were replaced, and we carefully matched the existing designs, with exact match mouldings and glazing bars. We used Accoya timber to make the doors, which is our first choice of timber because of its incredible strength and stability. The doors were also glazed with single glazed, restoration, laminated glass. On the master doors we fitted an Espagnolette bolt locking system in keeping with the original design.

Grade II listed French doors

Another set of French doors that we were asked to repair and restore on a listed building was the derelict Grade II listed White Lion hotel in Cobham (above), which was being turned into high end retirement apartments, and features sash windows dating back to the 1700s. Again, a complex mixture of repair and replacement work was required for this unique building.

Listed property with French doors & sash windows

At the back of the property (above) we partly replaced and refurbished the French doors that feature an elegant fanlight. We carefully re-glazed the fanlight with single glazed restoration glass as the original glass had been damaged. We repaired damaged glass, timber and beads on the sash window side lights, and freed and lubricated the sashes and pulleys. The doors were carefully replicated and fitted with new laminated single glazing and full perimeter draught proofing to improve insulation.


At Timbawood we specialise in the sensitive replacement and repair of timber windows and doors for period, listed and conservation properties, including sash windows, casement windows, French doors, front doors and bifold doors.

To speak to one of our specialists about your project, or to arrange a free survey or quotation, please get in touch on 020 8893 4889. We cover properties throughout London and the Home Counties.