Do I need planning permission for a rear extension?

For many people, extending their home will be the first taste of building or development work that they may have an involvement with. This may lead you to ask yourself “Do I need planning permission for a single rear storey extension?”.

In this article, I’ll try and answer that question although the answer will vary depending on your circumstances.

Many people add an extension to their property. The reasons for adding an extension include the following –

• Growing families and the need for additional space
• Adding a home office, a larger kitchen
• Simply adding value to the property

Extensions under permitted development

So, do you need planning permission for an extension?

Well, it depends.

If you are planning on adding a single storey rear extension to your property it is often covered by permitted development.

You can learn more about permitted development by reading Planning Permission vs. Permitted Development

To be considered permitted development the extension should adhere to the following criteria – 

• Materials used must be in keeping with the existing house
• The extension must not exceed 3 meters in depth from the original rear elevation for terraced houses and semi-detached and 4 meters for detached houses
• It must not exceed 4 meters to the highest part or 3 meters to the eaves if within 2m of a boundary
• It cannot include a verandah, balcony or raised platform
• In a conservation area it cannot be clad in stone, pebble dash, render, timber, plastic or tiles

As a general rule, if your single storey rear extension plans adhere to the above points, generally you won’t require planning permission and the permitted development rules will apply.

When you will need planning permission

There are a few situations, however, where planning permission will be required for a single storey rear extension. These include –

• If your property is a listed building.
• If your property does not benefit from ‘permitted development rights’.
• If your extension creates a balcony, veranda, or raised platform.
• If your extension takes up more than 50% of the total area of the curtilage.
• If your extension is on a wall which forms the principal elevation of the original dwelling.

If any of the above points apply to your development project, then you would have to apply for planning permission from the Local Planning Authority.

Extensions, like all building projects, can contain their own unique issues. If you are unsure about your extension project and whether it falls under the banner of permitted development or planning permission or for any other enquiries, please get in touch and Simple Planning Solutions can advise on the most efficient way to proceed with your development plans.