Understanding Planning Permission

Planning permission is formal consent from your local planning authority (usually your district, borough or unitary council) to carry out certain building work or change how land or a building is used. It exists so that development happens in a way that balances the interests of the person building with those of neighbours and the wider community.

When do you need planning permission?

You generally need permission to build something new, make a major change to a building (such as a large extension), or change the use of a building — for example turning a house into flats or a shop into a café. You may not need permission for many smaller domestic projects, which fall under permitted development rights (see below).

Common projects that usually require an application include: a side or rear extension beyond the permitted development limits, a new dwelling, a loft conversion that alters the roof shape, a dropped kerb onto a classified road, and most work to a listed building or in a conservation area.

Permitted development rights

Permitted development (PD) lets you carry out specific works without a full application, within strict size and siting limits set out in national legislation. Typical examples include modest single-storey rear extensions, many porches, and certain outbuildings. The limits are detailed and easy to exceed, and PD rights can be removed in conservation areas, on listed buildings, or by an "Article 4 direction". If in doubt, apply for a Lawful Development Certificate — it confirms in writing that your project is lawful and is invaluable when you come to sell.

The main types of application

• Householder — extensions and alterations to a single home.
• Full planning permission — new buildings, changes of use, multiple dwellings.
• Outline permission — establishes the principle of development, with details ("reserved matters") to follow.
• Prior approval — a lighter-touch route for certain changes (e.g. some larger rear extensions, some change-of-use classes) where the council checks specific impacts only.
• Listed building consent — required for works to a listed building, in addition to any planning permission.

How long does it take?

The statutory target is 8 weeks for householder and minor applications, and 13 weeks for major developments (16 weeks where an Environmental Impact Assessment is needed). In practice many councils ask for an extension of time. There is a public consultation period — usually 21 days — during which neighbours and anyone else can comment.

What happens if you build without permission?

Building without required permission is not automatically a criminal offence, but the council can serve an enforcement notice requiring you to undo the work. You can apply for retrospective permission, but there is no guarantee it will be granted. Time limits apply to enforcement, and the rules around them changed under recent legislation, so never rely on "they won't notice" — unauthorised work can block a future sale and prove far more expensive to resolve.