LDC
What is a Lawful Development Certificate — and do you need one?
Anatolie Chiriac · Graduate Architectural Technologist
Last reviewed August 2026. Relates to England. General guidance, not advice on a specific property.
A Lawful Development Certificate, or LDC, is a formal decision by the local planning authority confirming that a development is lawful. It is not planning permission. It is the opposite: proof that permission is not required, because the work falls within permitted development rights.
Two kinds
- A certificate for proposed development, under section 192 of the Town and Country Planning Act 1990, obtained before you build.
- A certificate for existing development, under section 191, obtained for work already carried out.
Why bother, if the work is already permitted?
Because permitted development is a set of conditions, not a category. Whether a scheme qualifies depends on volumes, heights, boundary distances and the building’s planning history — and the burden of proving it falls on you, not the council. An LDC converts an assumption into a legally binding confirmation.
The practical moment this matters is sale. A buyer’s solicitor will ask what authorised the extension. Without a certificate, the answer is an opinion, and the usual outcome is a delayed transaction, an indemnity policy, or a price reduction.
What the council actually decides
An LDC application is decided strictly on evidence and planning law. The merits of the design form no part of it — an inspector cannot refuse a certificate because a scheme is ugly, and cannot grant one because it is attractive. What matters is whether the submitted drawings show, on the balance of probabilities, that every relevant limit and condition is met.
That last phrase does real work. Certificates are regularly refused not because a scheme breached a limit, but because the drawings were not precise enough to prove it did not. Dimensions that appear on one view and not another, or figures that contradict each other between drawings, are enough to fail.
What it costs
A certificate for proposed development costs half the fee of the equivalent householder planning application, plus drawing preparation. Against the cost of unwinding unauthorised work — or discovering the problem mid-sale — it is inexpensive.
How we approach it
We check a scheme against the relevant class and its conditions before anything is finalised, and we say plainly when something cannot be resolved without a certificate rather than assuming it will be fine. Where the facts are contested or unclear, that is exactly when a certificate is worth having.
General guidance on the position in England, not advice on a specific property.
Whether these rules let you build what you have in mind depends on measured dimensions and your property’s planning history — neither of which can be settled from an article. If you want a view on your own house, send us the details.
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