Many house extensions fall under permitted development rights, meaning no planning application is needed. However, there are important restrictions to understand.
Single-storey rear extensions can typically be built under permitted development if they extend no more than 4m beyond the rear wall for detached houses, or 3m for other houses. Height must not exceed 4m.
You will always need planning permission if your property is listed, in a conservation area, or an Area of Outstanding Natural Beauty. Your contractor can advise on whether your project needs permission. Find extension specialists.
Frequently Asked Questions
How long does planning permission take?
Typically 8 weeks from submission to decision for householder applications in England.
How much does planning permission cost?
A householder planning application costs £206 in England (£230 in Wales, £207 in Scotland).
What is permitted development?
Permitted development allows certain types of work without planning permission, subject to limits and conditions. Not all properties have permitted development rights.
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