A Lawful Development Certificate (LDC) is a formal document from your local planning authority confirming that a building project is lawful — either that existing work didn’t need planning permission, or that a proposed project falls within permitted development and won’t need it.
The two types of LDC
- Proposed (LDCP) — confirms before you build that your planned project is permitted development.
- Existing (LDCE) — confirms that work already carried out, or an existing use, is lawful.
Do you actually need one?
An LDC isn’t compulsory for permitted-development projects, but it’s strongly recommended. It removes doubt, protects you from future enforcement action, and is often requested by buyers’ solicitors when you sell. Spending a few hundred pounds now can save a sale falling through later.
How to apply, cost and timing
You apply to your council, usually through the Planning Portal, with a plan of the site and drawings showing the proposal. The fee for a householder LDC is roughly half the cost of a full householder planning application, and a decision typically takes around eight weeks. Unlike planning permission, the council isn’t judging whether your project is a good idea — only whether it is lawful.
Not sure whether you need an LDC or full permission? Read Lawful Development Certificate vs planning permission, or check the permitted development rules first.
Unformed’s Planning Review assesses whether your scheme is likely to qualify for an LDC and flags anything that could push it into a full 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.