Common Projects: do I need planning permission?

Do I need planning permission for this common project? It is one of the questions we hear most often at Planning Geek. This section brings together practical project guides for homes, businesses and land, alongside the planning basics that explain why something does — or does not — need permission.

Some projects are not development at all. Others need a planning application, while many can be carried out using permitted development rights under the GPDO. The answer can also depend on the building, its lawful use, its planning history and whether particular rights have been removed.

You can browse the Planning Basics & Common Projects Index, or start with the planning-basics guides on what counts as development, the planning unit, curtilage and the principal elevation.

You can also reach this section via commonproject.co.uk

Start with the project, then check the planning route

A project can fall into several different planning routes. It may not be development under section 55 of the Town and Country Planning Act 1990; it may be development that already has planning permission through the GPDO; or it may need an application to the local planning authority.

That is why two apparently similar projects can have different answers. A window alteration to a house may have permitted development rights while the same alteration to a flat does not. A detached garage used as a hobby room can raise different questions from one occupied independently as a home. A planning condition or Article 4 direction can also remove a right which would normally exist.

Useful checks before you start work

• check the lawful use of the land or building
• check the planning history and any conditions
• identify whether the proposal is development at all
• check the exact permitted development class rather than relying on a general rule
• check whether the property is listed or on protected land
• check whether an Article 4 direction affects the right
• remember that Building Regulations and planning permission are separate

If certainty matters before spending money, selling or remortgaging, a certificate of lawfulness may be appropriate. If permission is required, see our planning applications section or ask us for a fee proposal.

Other Common Projects

Page Updated: 2nd September 2026