If you are unsure whether your building project requires planning permission or to make sure an existing use of a building is lawful for planning purposes, you can submit a "Certificate of Lawfulness".
This means we'll provide you with an official "Yes" or "No".
If you want to know if your project requires planning permission before you start building, you would submit an application for "Certificate of Lawfulness – for a proposed use".
This means we'll confirm if the project you plan to do in the future requires planning permission or not.
If you have already completed the project and want to know whether the building work you've done requires (and still requires) planning permission, you would submit an application for "Certificate of Lawfulness – for an existing use".
This means we'll confirm if the project you've finished was permitted development or if it's been completed for such a long time that it's become exempt from planning enforcement and has planning permission "by default".
Depending on the type of application you intend to submit, there may be additional documents that are required.