Lawful Development Certificate – do I need one for my new extension?

Making use of your Permitted Development Rights? Get a Lawful Development Certificate now to avoid headaches in the future. It’s quick, simple, and affordable.

What is a lawful development certificate?

A lawful development certificate (also known as a certificate of lawfulness) acts as a form of official proof signed by your local authority that the project was legal when construction started. This is very useful when it comes to selling your house or if planning policies change, as you can provide evidence that your project complied with standards at the time.

An LDC isn’t a legal requirement for you to start your build, but they’re a wise investment and stop issues with your local authority and future buyers down the line if you need to prove the legality of the build. Potential home buyers are very risk-averse and if they see that a house has been extended they will want to see proof that the extension meets the rules in place at the time, and a lawful development certificate will provide them with the peace of mind that the extension is legal.

Why do I need an LDC if I'm using Permitted Development Rights?

If you’re making use of your Permitted Development Rights, LDCs mean you’ve got documentation from your local authority that your planned project meets legal requirements without needing to submit a full planning application – so they’re pretty handy, and something of an asset when it comes to selling.

After you’ve checked that there’s not an Article 4 restriction removing your Permitted Development Rights, making use of them is a build-by-numbers exercise, as the rules around what you can and can’t build are fairly clear. 

Our blog has more information, and remember you can also add a couple of storeys by building upwards and well as outwards into your garden. 

lawful development certificate
Make sure your extension is legal with an affordable LDC

In addition, there are certain conditions that apply – but the majority of houses have some kind of permitted development rights attached to them. Although it seems like just another expense, it’s not a big one, and with good plans by an architect by your side, you’re almost certain to have it approved and you can start construction with confidence, knowing your project is 100% compliant. 

Even if you extend your house and then move out years later, the LDC is proof that whatever you built at the time was legal, even if planning policies and the conditions Permitted Development Rights change. 

Do I absolutely need an Lawful Development Certificate?

Given how simple it is to get one (the application is straightforward, you should already have the architect’s plans, and it’s inexpensive) you’re shooting yourself in the foot if you don’t bother to get one.

Why? If you’re extending to sell on, future buyers tends to be advised to ask for them will be wary of putting an offer in an extended property if there’s no proof the build adhered to building guidelines. Nobody wants to buy a house where there’s a risk they might have to demolish the build or face a fine!

It’s possible to get a lawful development certificates in retrospect, but that’s also a risky bet. Not only does it cost twice as much, if your extension breaches any condition or the dimensions fall outside PD dimensions, the local authority will really throw the book at you and you might be obliged to demolish what you’ve built. Don’t take the risk! 

What do I need to apply?

Applying for a lawful development certificate is actually pretty simple, and well worth the effort. All you need to apply is:

  • An application form
  • Evidence verifying the information within the application – such your architectural plans and elevations. 
  • A site location plan
  • A fee of £103 (50% of a full planning permission application)

Your architect will often help out with this section for a nominal fee – and it takes a weight off your shoulders, so ask!

How long does it take to get an LDC?

Once you submit your application with all your documentation, you might be waiting up to 8 weeks for a decision, although this generally happens a little quicker with lawful development certificates.

If your application hasn’t been decided (this is unusual if you’ve had professional input) or gets rejected, then you can appeal. These are, however, time-consuming and will incur further costs so investing in help from professionals from the outset is a good idea. 

Get the professionals in!

If you’ve got plans to extend and make the most of your Permitted Development Rights, save yourself the stress and headache and come and speak to us. We can help you with your design and submit your Lawful Development Certificate, so you can start building with confidence! Drop us a line on our chat, send us a message or give us a call on 0121 455 0032. Let’s get started on your project!

Why Lapworth Architects?


Our 20+ years of work mean great design and good relationships with planning departments across the region to give our projects the best chance of getting your planning permission and starting building.


Your budget is tailored to your needs so you’re always on top of your costs. We’re proud to offer excellent value for money for our services, from design and planning right through to build.


Our breadth of knowledge makes us an efficient and sustainable choice of local architect, and we have a real vested interest in improving our own built environment right here in the West Midlands.


At whatever stage you’re at with your project, if you’re looking for honest, quality advice from professionals, chat to us, leave us a message or call us on the number at the top of the page. Let’s talk!