It’s a common confusion: a Lawful Development Certificate (LDC) and planning permission are not the same thing, and you generally need one or the other — not both. The difference comes down to whether your project needs permission at all.
The core difference
- A Lawful Development Certificate confirms that your project is permitted development and therefore does NOT need planning permission. The council checks lawfulness, not merits.
- Planning permission is an actual grant of consent for a project that is not permitted development. The council weighs the impact on neighbours, design and the area.
Which route applies to you?
If your project sits within the permitted-development limits, the LDC route is faster, cheaper and lower-risk. If it exceeds those limits — a large extension, anything at the front, work to a flat or listed building, or a home on designated land — you’ll need to apply for planning permission and the council can refuse it.
Cost and time compared
- LDC: roughly half the householder planning fee, around eight weeks, decided on lawfulness only.
- Planning permission: full householder fee, around eight weeks, decided on planning merits — and it can be refused or granted with conditions.
If you’re not sure
Start by checking whether you’re within permitted development — see do I need planning permission for an extension? and what is an LDC?. Many councils also offer paid pre-application advice.
Unformed’s Planning Review tells you which route your scheme is likely to need and what to fix before you submit either application.
This guide is general information, not legal or planning advice. Planning rules change over time and are applied differently by each local planning authority (LPA). Always confirm the position with your council before starting work. Unformed’s Planning Review gives an AI-assisted risk assessment of a scheme but does not guarantee any planning outcome.