How Long Does Planning Permission Last?

When planning permission is granted in the UK, it does not last forever. There is a fixed time limit attached, and if you do not begin development within that period, the permission will expire. Understanding how long planning permission lasts, when it expires, and what steps are needed to keep it valid is crucial for anyone undertaking building works or development. Whether you are a homeowner planning an extension or a developer working on a larger site, failing to act within the permission window can result in lost time, additional costs, and delays to your project.

With the rising complexity of development and the challenges of securing approvals, especially on sensitive or high-value sites, knowing how to manage the lifespan of your planning permission is more important than ever.

Does Planning Permission Expire?

Yes, all planning permissions have an expiry date. Once the approval is granted by a local planning authority, you are given a specific time period in which to begin the development. If you do not start work before this deadline, the permission will lapse and you will need to reapply. This rule is designed to ensure that developments progress in a timely way and that planning decisions remain relevant to current policy and site conditions.

Expired planning permission cannot be renewed in the traditional sense. If it runs out, a new application must be made, which will be assessed afresh against any updated planning policies, regulations, or site constraints. This could result in refusal even if your original application was approved.

How Long is Planning Permission Valid For?

In most cases, full planning permission is valid for three years from the date the decision notice is issued. This three-year rule applies to the vast majority of applications, including householder developments, change of use, and new build schemes.

Outline planning permission is slightly different. It usually gives you three years to submit the 'reserved matters' application (the detailed design stage). Once the reserved matters are approved, you typically have two years from that date to begin the development. This two-stage process is often used for large or complex schemes where details are not finalised during the initial application.

Some permissions may have a different time limit, but this must be explicitly stated in the decision notice. Occasionally, local authorities will reduce the time limit to encourage faster delivery, especially for housing developments.

What Counts as ‘Starting’ Development?

To prevent planning permission from expiring, you must begin the development before the expiry date. This does not mean the entire project must be completed. The law requires a “material start” to be made, and the Town and Country Planning Act 1990 outlines specific criteria for this.

Examples of what counts as a material start include digging foundations, beginning groundworks, installing drainage or services, and erecting structural elements. Simply clearing the site, marking it out, or carrying out surveys is not enough. The work must be significant and demonstrate a genuine commitment to commencing the development.

It is essential that the start is lawful. You must discharge any pre-commencement conditions, such as submitting construction management plans or ecological surveys, before carrying out physical work. Starting without doing so could render the development unauthorised, even if done within the three-year timeframe.

Proving Development Has Commenced

To prove that work started in time, you should keep accurate records. Photographs, dated correspondence, contractor invoices, and progress reports can all be useful. In some cases, local authorities will request evidence if there is doubt about whether development began before permission expired. If needed, you can apply for a lawful development certificate to confirm the commencement was valid.

For large-scale projects, especially those phased over many years, you may begin work on part of the site to preserve the planning permission for the whole area. However, this must be done in accordance with the approved plans and conditions.

What Happens if Planning Permission Expires?

If your planning permission expires before work begins, you cannot legally start the development. You must submit a new application and go through the planning process again. This means preparing new plans, paying another fee, and allowing time for public consultation and assessment.

Planning policy, local priorities, and site constraints may have changed since your original permission was granted. For example, flood zones may have been reclassified, biodiversity requirements introduced, or new design standards adopted. Your new application will be judged against the current framework, and there is no guarantee it will be approved again.

In some situations, developers reapply just before the expiry date with a ‘repeat’ application that is identical or slightly amended. This can work if policies remain supportive, but it carries risk and should not be used as a substitute for starting the work on time.

Can You Extend Planning Permission?

There is no formal process to extend planning permission once granted. Prior to 2013, extensions were allowed under transitional arrangements, but these have ended. The only way to retain the approval is to begin development within the time limit.

Some applicants choose to reapply with minor changes, making use of streamlined processes such as section 73 applications, which allow variation of conditions without changing the development significantly. However, even these applications are assessed on merit, and success is not guaranteed.

Tips to Avoid Expiry

If you receive planning permission and cannot begin work immediately, keep track of deadlines and set reminders well in advance. Review any conditions attached to your approval, particularly those requiring discharge before commencement. Engage with professionals early to ensure technical documents are submitted on time.

Where delays are unavoidable, such as financial constraints or legal issues, consider starting a small part of the approved works to lawfully implement the permission. Always take advice before doing this to ensure the start is valid and compliant with conditions.

Sustainability and Long-Term Strategy

Delays in implementation can have implications beyond planning compliance. Building regulations and environmental standards are continually evolving. Waiting several years to start may mean revising your plans to meet new thermal performance or carbon emissions standards. It is also worth considering supply chain costs and interest rate movements when deciding when to start work.

For long-term projects, a clear phasing strategy can ensure planning permissions are preserved while allowing for flexibility in construction. Developers should take legal advice and work closely with their planning consultants to structure large schemes effectively.

Example in Practice

A landowner in Hertfordshire secured full planning permission to build four detached houses on a plot in 2021. Due to funding delays, construction did not begin until early 2024. To avoid expiry, the developer instructed groundworkers to dig and pour foundations on one of the plots in late 2023, after discharging all pre-commencement conditions. This action lawfully implemented the permission, allowing the remaining houses to be built at a later date without reapplying. This example shows how proactive planning and a clear strategy can keep projects on track.

Conclusion

Planning permission is a valuable asset, but it is time-limited. Understanding how long it lasts, what counts as starting, and the risks of letting it expire is essential for anyone involved in development. By acting early, meeting conditions, and keeping accurate records, you can protect your approval and move your project forward without costly delays.