What Is a Lawful Development Certificate, and Do You Need One?

If your extension or loft conversion falls within permitted development, you don’t need planning permission. But “I didn’t need it” is hard to prove on paper, especially years later when you come to sell. That’s what a lawful development certificate is for.

What a lawful development certificate is

A lawful development certificate (often shortened to LDC) is a formal decision from your local council confirming that a use of land, or a piece of building work, is lawful. It isn’t planning permission. It’s confirmation that planning permission either isn’t needed, or that what’s already there can’t be challenged.

The two types

There are two kinds of certificate, and they do different jobs.

• Proposed use or development. This confirms that something you’re planning to do would be lawful. It’s the one most homeowners need, usually to confirm that an extension or loft conversion falls within permitted development before work starts.
• Existing use or development. This confirms that something already there is lawful, even if it never had planning permission, because the time limit for the council to take enforcement action has passed.

Why get one for a permitted development project?

A certificate for a proposed project isn’t compulsory. You can rely on permitted development without one. We still recommend it for most projects, for three reasons:

• Certainty before you build. Permitted development rules are detailed, and it’s easy to go slightly over a limit without realising. A certificate means the council has checked your design against the rules before you spend money on construction.
• Selling your home. A buyer’s solicitor will ask whether work had planning permission. If it didn’t need it, the certificate answers the question in one document.
• Peace of mind with neighbours. If someone complains to the council later, the certificate shows the work was confirmed as lawful.

Certificates for existing work

Sometimes work was carried out years ago without permission, perhaps by a previous owner. A certificate for existing development can confirm it’s now immune from enforcement, provided you can show it has been in place long enough.

The time limits changed in England on 25 April 2024. For work and changes of use carried out on or after that date, the council generally has ten years to take enforcement action. For building work substantially completed before that date, and for changes of use to a single house that happened before it, the older four-year limit still applies.

The burden of proof is on you. You’ll need evidence such as dated photographs, invoices, council tax records or statements showing when the work was completed or the use began.

How the process works

1. Prepare the drawings and information. For a proposed project, that means clear drawings showing the existing and proposed house, with enough detail for the council to check the design against the permitted development limits.
2. Submit the application. Applications go to your local council, usually through the Planning Portal.
3. Wait for a decision. The council should decide within eight weeks of validating the application.

The fee for a proposed-use certificate is half the fee for the equivalent planning application. Fees for existing-use certificates are higher.

There’s no public consultation in the way there is with a planning application. The council isn’t judging whether the design is attractive or acceptable, only whether it meets the rules.

What if the council refuses?

A refusal means the council doesn’t think the project falls within permitted development as designed. That usually leaves two options: adjust the design to bring it within the limits, or apply for planning permission instead. Either way, it’s far better to find out before work starts than after.

How we help

We prepare the drawings and supporting information for lawful development certificate applications, checking your design against the permitted development rules as we go. If it turns out your project does need planning permission, we can prepare that application instead, and then take the design through to building regulations and construction-ready drawings.

Not sure whether your project falls within permitted development? Run your address through our Project Checker for a first look at any planning constraints, or get in touch and tell us what you’re planning.