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How Long Does Planning Permission Last?

Planning Permission

The quick answer to ‘how long does planning permission last’ is…. 3 years from the date your householder planning application is approved.

Although that might seem like an easy answer, there are a number of factors and steps to consider to make sure that this time limit applies to your specific project.

All our in-house planning consultants have previously worked as local authority planning officers. They have a very good understanding of how the planning system works in practice.

We have prepared this comprehensive article which goes into detail about how long planning permissions lasts. We also answer some other related frequently asked questions.

1. How long does planning permission last for an extension?

This depends on the type of planning permission you have or want to obtain.

1.1. Householder planning application

For most projects relating to extensions, you would apply using what’s called a Householder planning application. This is the application form used for adding extensions to a house or construction works within the boundary and garden of a house.

When your planning application is approved, there will be several conditions attached to your Decision Notice. One of those conditions will relate to when the planning permission expires. When it comes to Householder planning applications, that expiry date is typically 3 years from the date the planning permission was issued.

So, when looking to answer the question ‘how long does planning permission last?’ the answer is, 3 years from the date the planning permission was granted.

1.2. What happens after 3 years?

After 3 years, if the planning permission has not been implemented (or construction works haven’t started), it expires.

You should not begin construction after the expiry date, because you would technically be in breach of your planning conditions. Once you have gone past the expiry date, your planning permission would no longer be valid.

1.3. How long does planning permission last for an outline application

How long does planning permission last for outline planning application is a little different. An outline planning application is usually only used on large development sites for new houses or large blocks of flats. They are useful when property developers are working on risky sites. It allows the developer to establish basic principles of development before deciding whether to spend more money on designing a full scheme.

For ‘outline planning permission’, the timeframes are different when compared to the householder applications discussed above. Unless otherwise stated, there is a 3-year period from the time of approval in which to submit the outstanding ‘reserved matters’ application. ‘Reserved matters’ include all the outstanding points which a developer may have chosen not to include in the original outline application.

Following the approval of the reserved matters, an additional 2 years is allowed for the permission to be implemented. This gives a total of up to 5 years to implement an outline planning permission.

2. Can I stop my planning application from expiring?

The short answer is, yes you can. But it’s not a straightforward process. There are still a few hoops to jump through.

2.1. The 3-year expiry rule

As highlighted above, the decision notice for your Householder planning application will include a condition relating to when the building works should start. We have taken a screenshot of a recent approval we were granted in Camden to highlight the wording of the time limit condition you might expect to see.

Plannign Decision Notice

The precise wording is important when trying to work out how long planning permission lasts. Some homeowners are under the misapprehension that once you start the development, you must finish it within 3 years, but that’s not strictly true.

All you have to do is ‘begin’ your development by that date.

2.2. What works can I carry out to avoid my permission from expiring?

Whether someone has started their building works is sometimes a grey area.

The technical legislation can be complex, but to summarise, a development or extension is considered to have started when a ‘material operation’ is carried out.

The Town and Country Planning Act provides a comprehensive definition of a ‘material operation’:

1. Any work of construction in the course of the erection of a building

2. Any work of demolition of a building

3. The digging of a trench which is to contain the foundations, or part of the foundations, of a building

4. The laying of any underground main or pipe to the foundations, or part of the foundations, of a building or to any such trench as is mentioned above

5. Any operation in the course of laying out or constructing a road or part of a road

6. Any change in the use of any land which constitutes material development

2.3. Digging A Trench

So, how does the above legislation apply to everyday homeowners wondering ‘how long does planning permission last?’

The most useful excerpt is ‘the digging of a trench which is to contain the foundations’.

Let’s apply this to a real-world example we see a lot. If you have planning permission for a single storey rear extension and your planning application expires in 4 weeks…. what can you do?

Our team at Adara have helped lots of homeowners in this exact same position.

The easy solution is to find a gardener, labourer or builder (you can even do it yourself), and ask them to dig a trench for your new foundations. We recently did exactly this for a homeowner whose extension application was about to expire. Below is a picture of what the builder prepared.

Picture of a Trench
A simple trench like this can be dug to stop your planning application from expiring

The above trench was sufficient to show the local planning authority that the approved scheme had been started. Once you have started your planning permission before the 3-year expiry date, this means you can then finish the extension whenever you wish.

2.4. Certificate of Lawful Development

Can I confirm with the local planning authority that construction works for my new extension have started?

Yes you can!

I was a local planning authority planning officer for a long time. When I first started, we would be given hundreds of Certificates of Lawful Development applications. These are usually used by homeowners looking for confirmation that their proposed extensions are Permitted Development and do not require planning permission.

However, this type of application can be used for other useful things. For example, you can apply to confirm that you have started building works within the required 3 year period.

If they deem your application to be lawful (which is the same as approving the application) this means you can then complete your extension whenever you wish.

3. Can You Renew or Extend Planning Permission?

Unfortunately, there is no way to renew or extend a planning permission.

If you have gone past the 3-year expiry date highlighted on your planning approval, you would need to resubmit a new planning application.

But, if you still have some time to go before the expiry date, you can explore ways to implement your current planning permission and apply for a Certificate of Lawful Development to confirm that with your local planning authority.

4. How to Reapply for Expired Planning Permission

4.1. Making the Application

If you wish to re-apply for planning permission, the process is quick and simple. The chances are either you or your architect submitted the original planning application through the Planning Portal. This is a government website where most planning applications in the UK are submitted.

4.2. Copy and Paste

Your Planning Portal dashboard has an option where you can find your previously submitted application.  You can then simply copy your application and create an entirely new one with the click of a button. All the details will be copied over which only leaves you to submit the application. Below is a screenshot showing how simple it is.

Image of the planning portal
Re-applying for planning permission can be done with the click of a button

4.3. How will my new application be assessed?

How your local planning authority assess your new application will be determined by how long after the expiry date it is submitted.

Reapplying soon after expiry: When I say ‘soon’, what I really mean is, within sufficient time that your local authority has not changed any important planning policies. The sooner you resubmit your application, the better chance it will have of being approved.

Reapplying after an extended period of time: If you reapply a number of years after the expiry date, you run the risk that policies might have changed. Or, perhaps a particular planning policy was previously ambiguous and the council have now decided to interpret it in a different way.

5. My planning permission has expired, what should I do?

5.1. Option 1 – reapply for exactly the same thing

If you would like to reapply for the same plans which have been previously approved but since expired, the only option is to reapply.

5.2. Option 2 – revise your plans

If it’s been some time and you would like to reapply but also make a few changes, that’s absolutely fine.

To improve your chances of success and speed up the process, here are a few tips.

Sometimes when reviewing applications, planning officers forget to check the planning history. Therefore, we think it’s always a good idea to ask your architect to make it very clear what parts of the new scheme have already been approved. At Adara, our architects often use a faint coloured hatching around extensions which have already been approved including the previous planning reference number.

This is a great idea because the second the planning officer looks at your plans, they will only be looking at the differences between the approved and proposed plans rather than re-assessing the entire scheme.

6. Do I need the help of a planning consultant?

This depends on the complexity of the problem. We would always suggest first discussing any planning matters with your architect. If they are confident they can resolve any specific planning issues then great!

However, if they are a bit apprehensive to take responsibility for a big decision, then we would always advise speaking to a planning consultant. They are experts of how the planning system works in practice.


If you have an existing planning permission which is about to expire, one of the best options is to implement the permission. We appreciate that the process can be a little confusing.

At Adara, half our team are former local authority planning officers. They have a very good understanding of exactly how the planning system works in practice. If you need any specific planning related questions answered, feel free to call us at any time. You can also book in a free 30 min consultation with one of our team anytime.

We’re always on hand to give advice. So if you’re wondering ‘how long does planning permission last?’, simply get in touch and we would be more than happy to help you.

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