Conservation Double Glazed Sash windows

Preserving the architectural heritage of listed buildings and properties within conservation areas presents a unique set of challenges. With stringent planning regulations and a commitment to maintaining the integrity of historic structures, restoration and replacement work on timber windows and doors require careful consideration and expertise.

In this article, we’ll explore the process of conserving and replacing windows and timber doors in these properties. From understanding what listed buildings are to navigating planning rules and using tailored solutions, find out how we approach upgrading conservation and listed building windows and doors.

What is a listed building?

A listed building is one that is considered to be architecturally or historically important on a national level, and therefore it’s protected. There are three grades:

  • Grade II: Buildings of special interest.
  • Grade II*: Buildings of particular importance.
  • Grade I: Buildings of exceptional importance.

Most listed buildings, over 90%, are Grade II.

To find out if your property is listed, you can check the Historic England National Heritage List for England (NHLE), which is the official record of protected historic buildings and sites.

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.

Bespoke listed and conservation windows

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.

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.