As a general guide, you need planning permission for new buildings, major alterations to existing buildings and to change the use of buildings or land.
If you are planning work on property or land that you own, it's your responsibility to seek out the necessary approvals, permissions or requests required. If you decide to go ahead without permission, you may end up having to put things back to how they were at your own cost.
When don't I need planning permission?
In some instances, planning permission is not required. This is known as permitted development. If you would like to know if your proposed work falls under permitted development you can check using the common projects section on the Planning Portal interactive guides and advice pages. More information can also be found in GOV.UK's Technical Guidance for Householders.
Some common projects that do not need planning permission include:
When do I need planning permission?
- Listed buildings – Internal or external alterations need an application for listed building consent
- Conservation area - If your property is in a conservation area, additional planning controls apply
- Signage - If you wish to erect a sign or advert, you may need advertisement consent
- Change of use - If you wish to change the use of a building, you may not need planning consent if the current and proposed use fall within the same use class. Most external building work associated with a change of use is likely to require planning permission.
If you need more information or are unsure whether your proposal requires planning permission, you can use our pre-application service.
Certificate of Lawful Development
Alternatively, for a formal decision of whether permission is required, you can apply for a lawful development certificate. This type of application clarifies if planning permission is required. If it is not required you will get a certificate which confirms this. If planning permission is required, you would then have to go on to make a formal planning application.
Exceptions for Southampton
In Southampton you will need planning permission to change a family house into a House in Multiple Occupation (HMO).
As well as getting planning permission you may need separate building control approval to ensure that the works reach certain standards so that the building is safe and energy efficient.