Lawful Development Certificate Fees, Evidence & the 10-Year Rule in London

What a Lawful Development Certificate is

A Lawful Development Certificate (LDC) is a formal document, issued by the local planning authority, confirming that a specific use or building operation is lawful. It is not a planning permission — it does not grant anything. Instead it records a legal fact: that the works either do not need planning permission, or that they can no longer be acted against.

That distinction matters. An LDC is decided on planning law and evidence, not on the merits or appearance of a scheme. The authority is not asking whether it likes the proposal; it is asking whether, as a matter of law, the works are permitted or immune. A certificate is the written proof that settles the question.

The two types: proposed and existing

There are two kinds of certificate, and it is worth being clear which one applies to your situation.

A certificate of proposed use or development confirms, before you build, that a project would be lawful — usually because it falls within permitted development and so needs no planning permission. You apply on the basis of drawings and a description of what you intend to do.

A certificate of existing use or development regularises something that has already been built or is already in use. It confirms that the existing works or use are lawful — either because they were permitted development when carried out, or because they have become immune from enforcement through the passage of time.

• Proposed LDC — forward-looking; confirms a planned project is permitted development, so no application for planning permission is required.
• Existing LDC — backward-looking; regularises works already done or a use already established, giving them a clean legal status.

Why get one even when you believe PD applies

Permitted development is a genuine right, so it is reasonable to ask why you would pay for a certificate confirming something you can already do. The answer is certainty, and certainty has real value at two moments.

The first is sale. When you come to sell, the buyer's solicitor will ask for evidence that past works were lawful. "We were told it was permitted development" is not evidence. An LDC is the document that answers the enquiry cleanly, avoids a renegotiation or a retention, and keeps a transaction moving. In prime London, where scrutiny on conveyancing is high, its absence can stall a sale.

The second is enforcement. If the authority ever questions your works, an existing-use certificate is a complete answer — the burden has already been discharged. Without one, you are relying on being able to reconstruct the argument and the evidence years later, possibly after the people and paperwork have moved on. A certificate obtained now, while the facts are fresh, is far cheaper than a dispute later.

The enforcement time limits and the 10-year rule

An existing-use certificate often rests on immunity: the idea that after enough time has passed, the authority can no longer take enforcement action, and the development becomes lawful. The time limits changed recently, so the current position matters.

In England, following the Levelling Up and Regeneration Act 2023, a single 10-year time limit now applies to all breaches of planning control for development that took place on or after 25 April 2024. This replaced the older split, under which some operational development and the change of use of a building to a single dwellinghouse became immune after only four years.

The change is not fully retrospective. Building operations that were substantially completed, or a change of use of a building to a single dwellinghouse that occurred, before 25 April 2024 generally remain subject to the old four-year limit. Because the applicable period turns on precisely what was done and when, and these transitional rules are easy to misjudge, the relevant time limit should always be confirmed for the specific facts before you rely on it.

• For development on or after 25 April 2024: a single 10-year enforcement limit for all breaches.
• For operations substantially completed, or change of use to a single dwellinghouse, before 25 April 2024: the former four-year limit may still apply under transitional provisions.
• Immunity is a matter of evidence and dates — never assume it without checking the facts for your property.

The fee and what it buys

A Lawful Development Certificate can be cheaper than a planning application, but how much you pay depends on which type you apply for. A certificate of proposed use or development is charged at half the fee for the equivalent planning application: for a householder-scale project that is £274, half the £548 householder application fee (both figures apply from 1 April 2026). A certificate of existing use or development is treated differently — it is charged at the full application rate for the equivalent works, so for householder-scale existing development the fee is the £548 householder figure, not the reduced £274. Which type you are in therefore changes the fee, so it is worth establishing that first.

In each case that is the statutory fee paid to the local authority for determining the application. It is separate from the professional cost of preparing the application — the drawings, the description of development, and the evidence needed to make the case. On our fixed-fee routes, that professional work is quoted before you commit, so you know the total position at the outset. You can see how our packages are structured at /packages/.

The process and the evidence you need

The application itself is straightforward in form, but it is only as strong as the evidence behind it. The authority makes its decision on the balance of probability, based on what you submit — so a well-evidenced application is what secures a clean certificate.

For a proposed certificate, the case is made on drawings and a precise description showing the works fall within the permitted development limits. For an existing certificate, the case is made on factual evidence establishing what was done or used, and when — enough to show it is lawful or that the time limit has passed.

• Proposed: accurate [[service:planning-drawings|drawings]] — existing and proposed plans and elevations — and a description demonstrating the works meet the permitted development criteria.
• Existing: dated evidence such as photographs, invoices, delivery notes, utility bills, council tax records, statutory declarations or sworn statements, and any historic correspondence.
• A location and site plan identifying the property, and a clear, unambiguous description of the use or operation the certificate is to cover.
• Consistency across the evidence — the authority is testing whether the account is more likely than not to be correct, so contradictions weaken the case.

Where an LDC fits with planning permission

An LDC is an alternative to planning permission for works that do not need it — not an add-on. If your project genuinely falls within permitted development, a proposed certificate confirms that and you proceed without a planning application. If it does not, you need planning permission and the certificate route is not available.

It is also worth remembering that a certificate deals only with planning. Even where an LDC confirms no planning permission is required, building regulations approval is usually still needed, with its own technical drawings and building control process. And in much of London — conservation areas, Article 4 directions, flats and maisonettes, and listed buildings — permitted development is restricted or removed, so whether a certificate is even the right tool must be checked for your address.

How we approach it

We start by establishing which route your property is actually in: whether the works are proposed or existing, whether permitted development is available at your address, and, for existing development, what the applicable time limit is on the facts. That assessment decides whether a certificate is the right instrument and which type to pursue.

From there we prepare the drawings, the description of development and the supporting evidence, and manage the submission. Send us your address and a description of the works, and we will advise the likely route — and whether an LDC is worth obtaining — before you commit to anything.