Tools · Do I need planning permission?

Do you need planning permission for a two storey extension?

A two storey rear extension can be permitted development within tight limits: no more than 3 metres deep, at least 7 metres from the rear boundary, and a matching roof.

Across the 240 councils we track, 79% of 41,743 decided two storey extension applications were approved, and typical council decision times run 8 to 10 weeks (public planning record to 8 Jul 2026).

First, about your home

What kind of home is it?

These permitted development rights apply to houses. Flats and maisonettes do not have them.

Is the building listed?

Work to a listed building usually needs listed building consent as well as planning permission. Outbuildings and boundary walls within the grounds of a listed building also need permission.

Is your home in a conservation area, National Park, the Broads, an area of outstanding natural beauty, or a World Heritage Site?

The rules call this designated land. Several permitted development rights are reduced or removed there. If you are not sure, your council's website says which areas are designated.

Now, about a two storey extension

Will it extend more than 3 metres beyond the original rear wall?
Will it come within 7 metres of the boundary opposite the rear wall?
Will any part of it be taller than the highest part of the existing roof?
Will any upstairs window face sideways towards a neighbour, without obscure glazing?
Counting existing extensions and outbuildings, will more than half of the land around the original house end up built on?

0 of 8 questions answered. Answer them all to see where your project stands. Not sure is always an option.

What actually happens in your council

If you do end up applying, real decisions show what to expect. Pick your council for its approval rate and typical decision time for two storey extension applications, from the public planning record.

The rules this checker tests, cited

England’s permitted development limits for a two storey extension, checked against the official guidance on 2026-07-17. Every rule links to its source.

Building Regulations are separate from planning. A two storey extension always needs Building Regulations approval: structure, fire safety, insulation, drainage and electrics are all covered.

If permission is needed: usually a £548 application in England (fees from 1 April 2026, indexed each year, per the official fee guide (opens in new tab)). A Lawful Development Certificate for a proposed project is £274.

If you take it forward

Real planning history beats promises. See which architects and agents know your council, check approval odds by council and project, or browse traders with public evidence:

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Common questions

Do I need planning permission for a two storey extension in England?

Often not: A two storey rear extension can be permitted development within tight limits: no more than 3 metres deep, at least 7 metres from the rear boundary, and a matching roof. Every limit has to be met, the rights apply to houses (not flats), and they can be removed locally by an Article 4 direction or a condition on an earlier permission. A Lawful Development Certificate from your council is the way to be certain.

Will it extend more than 3 metres beyond the original rear wall?

An extension of more than one storey must not extend beyond the original rear wall by more than 3 metres. Source: GPDO Schedule 2, Part 1, Class A, paragraph A.1(h).

Will it come within 7 metres of the boundary opposite the rear wall?

An extension of more than one storey must be at least 7 metres from the rear boundary. Source: GPDO Schedule 2, Part 1, Class A, paragraph A.1(h).

Will any part of it be taller than the highest part of the existing roof?

An extension must not be taller than the highest part of the existing house roof, and the roof pitch of the extension should match the original house as far as practicable. Source: GPDO Schedule 2, Part 1, Class A, paragraphs A.1(a) and A.3(b).

Will any upstairs window face sideways towards a neighbour, without obscure glazing?

Upper floor windows in a side elevation must be obscure glazed, and only open above 1.7 metres from the floor. Source: GPDO Schedule 2, Part 1, Class A, paragraph A.3(c).

How much does a planning application for a two storey extension cost?

If permission is needed, this kind of project is usually a £548 application in England (fees from 1 April 2026, indexed annually). A Lawful Development Certificate for a proposed project costs half the application fee.

Guidance from the public rules, not legal advice. Your council has the final say. The rules on this page are England law; Wales, Scotland and Northern Ireland have their own versions.

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