Conservation Double Glazed Sash windows

Bespoke Listed Windows & Conservation Windows

Restoration and replacement work on timber windows and doors on listed buildings and conservation properties can be difficult to get planning permission for, due to the architecturally sensitive nature of carrying out work on period windows and doors.

But at Timbawood, we have been able to fulfil the strict planning criteria for heritage windows and doors on listed buildings in over 30 unique planning authorities across London and the Home Counties, including Islington, Westminster and Richmond – due to our comprehensive range of specialist services. We have also carried out specialist restoration work on properties in Conservation Areas under Article 4 in many more authorities, including Wandsworth, Lambeth, and Kensington & Chelsea*.

The specialist services we offer for listed and conservation properties is unique to each project, and includes exact-match replacement and part replacement of sash windows, casement windows and a wide range of doors.

From our workshop in West London, we are able to offer bespoke glazing options including slimline double glazing and restoration glass – which has the slightly uneven look of the original period glass – the finest timbers, and traditional techniques including hand-puttying and hand painting for a truly authentic finish.

Our service also includes helping our clients put together listed building planning applications by supplying full detailed CAD designs for council approval.

Grade II Listed Building with our Sash windows and French doorsHave a look at our case study of the restoration and replacement work we carried out on the sash windows and French doors on a unique Grade II Listed building in West London (above), for an example of the craftsmanship and process involved. 

In 26 of the planning authorities, we have installed our elegant Timbalite slimline double glazing, which looks just like single glazing, on listed buildings to maximise the thermal and acoustic performance of the windows and doors without compromising the design and heritage of these unique buildings*.

We have used slimline double glazing on over 350 projects in total.

See below for the planning authorities where we have worked on listed and conservation properties:


Basingstoke & Deane Borough Council
Brentwood Borough Council
Broxbourne Borough Council
Chichester District Council
City of London
City of Westminster
Ealing Council
East Hampshire District Council
Elmbridge Borough Council
Fareham Borough Council
Hart District Council
Horsham District Council
London Borough of Hackney
London Borough of Hounslow
London Borough Of Islington
London Borough Of Richmond Upon Thames
Merton Council
Mole Valley District Council
Rother District Council
Royal Borough of Greenwich
Royal Borough of Kingston upon Thames
Royal Borough of Windsor & Maidenhead
Runnymede Borough Council
South Downs National Park Authority
Southwark Council
Spelthorne Borough Council
Tandridge District Council
Three Rivers District Council
West Berkshire Council
Wycombe District Council


Brent Council
Lambeth Council
Merton Council
The Royal Borough Of Kensington & Chelsea
Wandsworth Council
Waverley Borough Council

At Timbawood we specialise in bespoke timber windows and doors for period, conservation and listed properties, including sash windows, casement windows, french doors, front doors, fire doors and bifold doors. To find out more about any of our products or to speak to one our specialists about the options available, please get in touch.

*Please contact your local planning officer before carrying out any works on listed or conservation properties. Each property is judged on a case by case basis depending on the condition and type of the windows/doors, and the nature of the proposed works.