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Replacement Windows

Advice on replacing windows in a historic or conservation area property.


Replacing windows in a historic or conservation area property

Please seek advice before making changes, as consent will be required if your building is Listed.  If your property is in a conservation area restrictions may also apply (under an Article 4 Direction).

If you undertake work without the necessary consents then the Council may take enforcement action against you. 

Why keeping old windows is important

The importance of historic windows, with their wide range of styles and ages, can vary. But evidence of craftsmanship, the survival of old and rare material and detailed design are all of value, and can make them of special interest. Windows are a significant architectural feature of many building types throughout our towns and villages. In historic buildings, the proportion, design and material of  windows are a well-considered architectural detail and make a fundamental contribution to the architectural interest of individual buildings and the wider character and appearance of conservation areas. Alternations to windows can significantly alter the disposition of a building's façade or affect the aesthetics of whole street scenes.

When repair is better than replacement

Historic windows of interest should be retained wherever possible using careful matching repair. They usually benefit from being constructed in high quality softwoods. With the right maintenance and repair, they are long lived and sustainable - making them cheaper than replacements.

The complete replacement of windows should normally be a last resort, and is rarely necessary. If the repair is beyond the skills of a good joiner or metal worker, an accurate copy should be made.

Replacing non-historic windows

Some windows, if they are later replacements which do not follow the historic pattern, may not contribute to the historic interest of your house and even spoil its appearance. You could consider replacing them with ones that match the historic pattern of your property to enhance it. But remember to get permission from the Council before you commission any work. 

When existing windows let in the cold

There are no reason why older windows should not be as energy efficient as new ones. Making sure they fit well will help reduce draughts and heat loss. Adding draught-stripping will help too. 

New windows need to comply with minimum energy efficiency requirements as part of the Building Regulations (Part L). This can be achieved either with double glazing or secondary glazing. For listed buildings and buildings in conservation areas, a case can be made for exemption where complying with required standards would unacceptably alter the character and appearance of the window. 

Plastic windows

Plastic windows would not be acceptable in a Listed Building. This is because their design and appearance would be out of keeping with the building. 

Wood remains the preferred material for windows in an unlisted property in a conservation area. However, plastic would be acceptable provided it is a well-designed high end product.

If new windows have been put in without permission

Please contact the Conservation Officer. They will be able to undertake a visit and advise on the options available to you.

Action against installation of inappropriate windows

We will need to see the windows and decide if they are suitable. If they are not, we will give you advice on how to put things right.

We are likely to take enforcement action when: 

  • They have been recently changed
  • They are visually significant (in terms of the appearance of the property or are in a prominent part of the property)
  • It is clear they are of inappropriate design and/or materials

We are unlikely to take enforcement action when:

  • The windows/doors have been in place for many years
  • They are not so visually significant (in terms of the appearance of the property or in a prominent part of the property)
  • The design/materials, whilst incorrect, are not so harmful as to warrant intervention.

For further advice, please email