Permitted Development Allowance

Permitted development allowances only apply to houses. Flats, other types of buildings, and maisonettes are not included in permitted development allowances. Therefore, when planning an extension to be sure that there are no constraints, it is important to check with a Local Planning Authority to see if the permitted development rights will apply to your extension.


During the exciting journey of building a home extension, getting planning permission is usually considered to be frustrating. However, it is necessary for your extension. If you start building an extension that requires planning consent without having one, you could receive a legal notice ordering your home extension to be demolished. We summarized various rules that you need to review concerning extension projects that need and do not need planning permission. Keep in mind that this list does not cover everything that needs to be reviewed and it is essential to check rules beforehand with your local planning authority or building professional - such as an architect - as well.

Permitted development rights

In planning law, there is an allowance for some small extensions to be built without having to submit a planning application to your local council under permitted development rights. As an example, some conservatories and loft conversions can be built without having to submit a planning application. However, since the rules are complex and confusing, getting professional advice would help your extension project not to have legal problems.

Typical projects that may be done within Permitted Development rights are:

Single-storey extension

If your extension project is a single-storey extension, you might not need planning permission to extend a semi-detached or terraced house by eight metres to the rear. Besides, there are height restrictions. For example, single-storey side extensions are allowed only if they are not more than 4-metres in height, and a side extension can not be more than half the width of the original house.

Two-storey extension

Two-storey extensions are only considered to be permitted developments if they do not extend beyond the rear wall of the house by more than 4 metres, and if they are no closer than 7 metres to the rear boundary. Besides, the upper side-facing windows need to be obscure glazing.

Please feel free to CONTACT US if you have any inquiries regarding your project.