Main Media

A Guide to Replacing Windows in Conservation Areas

Design Insulation Light Sustainability Windows

Choosing white plastic frames for a traditional home can completely undermine its style and character. It may also be against the law if you live in a conservation area or listed building. In this guide, we explain how to find out if building regulations apply to your home. We’ll also show how to navigate the planning process so that your new windows please the council, your neighbours and, most importantly – you!

Jump to a section

The significance of traditional domestic windows

Listed buildings

What is a conservation area?

What is Article 4?

Acceptable styles and glazing

The planning process

The significance of traditional domestic windows

Historic England says that ‘the loss of traditional windows from our older buildings poses one of the major threats to our heritage’. 



Left: Historically inappropriate windows in an early 19th-century terraced house.
Right: Windows of the correct pattern reinstated. Image courtesy of Historic England

The issue isn’t only that traditional timber windows are falling into disrepair. Many replacements are unfaithful replicas and unsympathetic to the property and local area.

According to Historic England, ‘replacement plastic (PVC-u) windows pose one of the greatest threats to the heritage value of historic areas, particularly in towns and villages. Despite attempts at improving the design of these windows, they are instantly recognisable because they cannot match the sections and proportions of historic joinery.’

You must follow specific laws when you replace windows in protected properties to preserve the history and appearance of historic areas. The most closely controlled properties are listed buildings. 


Listed buildings


If you live in a listed building, you need permission from your local authority’s planning department before carrying out any work on replacing your windows. If you don’t get full consent, you could be breaking the law and liable for the cost of undoing any unauthorised work. All listed buildings in England can be found on the National Heritage List

If you live in a listed building, your local planning authority will expect your application to clearly show how you intend to preserve the building’s architectural or historical appeal. This usually means matching the same design and construction as the original windows as closely as possible. 

What is a conservation area?


There are around 10,000 conservation areas in England with extra planning controls and considerations that protect architectural and historical interests. Local councils decide most of these areas. 59% of conservation areas are rural, and 41% are in urban areas. In total, these protected areas cover 2,938 square kilometres (an area larger than Luxembourg).

Find out if you live in a conservation area by contacting your local planning authority (LPA). 

What is Article 4?

Homeowners who don’t live in listed buildings or conservation areas are free to make minor alterations to their homes as long as they comply with applicable Building Regulations. This is known as ‘permitted development rights’.

However, for listed buildings and conservation areas, ‘Article 4 Directions’ restrict the work you can do without planning permission. These rules differ by council but generally require your replacement windows to preserve or enhance the local area's overall character.  

Matching the original window style is also important. For example, a proposal to replace traditional sash windows (that slide open vertically) with modern casement windows (that swing open like a door) is likely to be denied. However, suppose, for some reason, your traditional property has casement windows, and you'd like to revert them to more fitting sash windows. In that case, your proposal is much more likely to be accepted. 

Acceptable styles and glazing for conservation areas and listed buildings

Councils are generally more supportive of repairing traditional windows than replacing them. But when windows are irreparable, replacements are accepted as long as they are faithful to the originals and in keeping with other properties in the area. 

Every detail makes a difference, from the proportion of the sashes to the opening lights arrangement, the thickness of the glazing profile, the bar details, and even the glass itself. The LPA may also consider the colour of the replacement frames. Fortunately, with our timber windows, there are thousands of shades to choose from. 


Double glazing may or may not be acceptable, depending on the type of glazing in your current windows. Single-glazed windows might have to stay that way. However, if it’s allowed, a well-designed double-glazed replacement such as a flush casement window (pictured above) can provide the ideal combination of authenticity and modern energy performance.  

Alternatively, we have the Regal box sash window, which is traditionally operated with a weights and pulley system to provide an ideal replacement for an original box sash window. It’s also available with single or double glazing, depending on your home’s requirements. 

The planning process

Here’s the process for gaining consent for new windows in listed and conservation areas in six steps:

  1. Research the appropriate style

Look at the windows of other homes on your street and in your local area to get a feel for the original, permitted style. 

  1. Check the planning status of the building and area

Find out if your home is a listed building or in a conservation area and whether Article 4 directions apply. If they do, look up the specific guidance for your local authority. 

  1. Consider your options and get advice

With the research and rules in mind, consider your options and whether your choice of new windows will have 'no material effect on your property's external appearance'. You may want to seek independent advice to ensure your planned replacement windows tick all the right boxes. 

  1. Prepare your planning application

If one is required, prepare a planning application that includes the window supplier’s specification and other supporting information. Expert help is really handy here. 

  1. Respond to queries from your Local Planning Authority

After submitting your application, respond to any queries for further information and modifications. 

  1. If refused, appeal or submit a revised plan

Find out exactly why your application was rejected (if it was). Go back to the planning stage to modify your proposal and bring your new windows closer to what your local planning authority requires. 


When it’s time to consider your options, take a look at our range of timber windows

Our sliding sash window in particular is designed to match local planning and architectural requirements while bringing elegance to any property.