Rear extension planning and design
A rear extension is the most common way to add kitchen and dining space. Whether yours needs planning permission depends on its depth, height, the type of house and what has already been built.
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What people usually want from a rear extension
- An open kitchen and dining space connected to the garden
- More natural light through glazed doors or rooflights
- A utility, boot room or downstairs shower room
- A better relationship between the existing rooms and the new space
The planning considerations
Single-storey rear extensions are one of the categories covered by permitted development rights, subject to detailed limits on depth, height and position, with tighter limits on designated land. Larger single-storey rear extensions can sometimes proceed under the prior approval neighbour consultation scheme instead of a full application.
Where the limits are exceeded, or the rights do not apply to your property, a householder planning application is the route.
Who this is for
- Homeowners wanting more ground-floor living space at the back of the house
- People who have been told their proposal is 'probably permitted development' and want that checked properly
- Owners of flats, listed buildings or homes in conservation areas, where different rules apply
Typical process
- Free planning check on the property and proposal.
- Free 15–20 minute call to discuss what you want to achieve.
- Written quote before any paid work begins.
- Design and drawings, then the planning or prior approval submission where needed.
Important things to be aware of
- Permitted development depth and height limits differ by house type and by whether the property is on designated land.
- Earlier extensions, including ones built by previous owners, can reduce or remove the remaining allowance.
- Party wall obligations and drainage build-over agreements are separate from planning and often apply.
Frequently asked questions
- How deep can a rear extension be?
- The permitted development limits depend on whether the house is detached, the extension's height and whether the property is on designated land, and larger extensions may need prior approval. The only reliable answer is one based on your property.
- What is the neighbour consultation scheme?
- It is a prior approval process for certain larger single-storey rear extensions. The council notifies adjoining neighbours, and if they object the council decides whether the impact is acceptable.
- Will a rear extension need building regulations approval?
- Yes, in almost all cases, whether or not planning permission is required. That is a separate technical stage.
Related pages
Official sources
Tell us about your project
Tell us about your property and what you would like to change. We review the enquiry and you can request a free 15–20 minute call to talk it through. We help homeowners in Hampshire, Surrey and Berkshire.
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