What an LDC is and what it isn't
A Lawful Development Certificate (LDC) is a legal document issued under Section 191 or 192 of the Town and Country Planning Act 1990 that confirms either (a) an existing use, building or operation is lawful, or (b) a proposed development would be lawful. It is not planning permission — it is the council formally agreeing that no permission is required. There are two flavours: Certificate of Lawfulness of Existing Use or Development (CLEUD, under s191), for work already done, and Certificate of Lawfulness of Proposed Use or Development (CLOPUD, under s192), for work you intend to do under permitted development. Once granted, the certificate is conclusive — a future buyer's solicitor will accept it as proof that the works are lawful and the property is saleable without dispute.
When you actually need one
You need an LDC in three main situations. First, when you have completed PD works and want belt-and-braces confirmation for a future sale — buyers' conveyancers increasingly demand certificates for rear extensions, loft conversions, and outbuildings before exchange. Second, when you are about to do PD works and want certainty that the council agrees they fall within Class A or Class B before you commit £80,000 to a build. Third, when works were done years ago without permission and you want to immunise them under the four-year rule (operational development) or ten-year rule (changes of use) — though the ten-year rule has now replaced the four-year rule for most cases under reforms that took effect April 2024.
Evidence you must submit
A CLEUD application requires evidence that the works are completed and the time period has elapsed. The strongest evidence is sworn statutory declarations from the homeowner and neighbours confirming the dates, supported by dated photographs, utility bills showing the property in its current form, invoices from builders, and council tax records. Hearsay is not enough — the burden of proof sits with the applicant and the standard is the balance of probabilities. For a CLOPUD, you submit detailed drawings (location plan, block plan, floor plans, elevations) just as you would for a planning application, but the council assesses only whether the proposal complies with the relevant PD class, not whether it is acceptable on planning merits.
Fees and timeline
The statutory fee for an LDC in 2026 is £138 for existing or proposed development on a single dwelling — half the rate of a householder planning application, reflecting that the council is only doing a legal compliance check rather than a planning judgement. Determination is meant to be 8 weeks but most London boroughs are running 6–10 weeks for LDCs in 2026, sometimes faster than planning applications because the assessment is more mechanical. There is no neighbour consultation and no site notice for an LDC — it is a private determination between you and the council. The certificate, once issued, runs with the land in perpetuity.
Refusal and appeal
Councils refuse LDCs when they believe either (a) the works don't comply with the claimed PD class, or (b) the evidence of completion or time elapsed is insufficient. Refusal rates for CLOPUDs are around 25% in London — usually because the design exceeds Class A volume limits or sits in an Article 4 zone the applicant missed. You can appeal to the Planning Inspectorate within 12 weeks, and LDC appeals have higher success rates than planning appeals (around 45%) because they turn on points of law rather than planning judgement. Better strategy: get pre-application confirmation in writing before submitting the LDC.
Why conveyancers ask for LDCs
Since 2020 the residential property market has become significantly more cautious about unauthorised works. Buyers' solicitors routinely ask sellers to produce an LDC for any rear extension, loft conversion, outbuilding or change of use, even when the work was clearly PD. Without an LDC, the buyer's lender may insist on indemnity insurance (£150–£400) or refuse to lend at all. If you are selling a London property with PD works completed in the last decade and don't have an LDC, get one before marketing — it removes friction at exchange and typically pays for itself in agreed sale price.
