The Ultimate Guide to Retrospective Planning Permission Post 2024
Retrospective planning permission provides landowners with a legal route to regularise development that has been carried out without prior planning approval. While unauthorised development is not automatically a criminal offence, it leaves property owners at risk of enforcement by the local planning authority (LPA).
A major change to the enforcement rules came into effect on 25 April 2024, abolishing the previous 4-year enforcement period and replacing it with a single 10-year rule across all types of planning breaches in England.
1. The Rule Change: From 4 Years to 10 Years
Before 25 April 2024, the time limits for enforcement in England were:
• 4 years for:
• Operational development (e.g. unauthorised building works)
• Unauthorised use of a building as a single dwellinghouse
• 10 years for:
• All other breaches, such as changes of use and breaches of conditions
What Changed?
Under powers introduced by the Levelling-up and Regeneration Act 2023, the Government brought into force a unified enforcement period on 25 April 2024. From this date:
• All breaches of planning control now become immune from enforcement after 10 years, regardless of the type of breach.
• The previous 4-year rule was abolished.
This means property owners who previously relied on the shorter 4-year period for building works or converting a building into a dwelling must now wait 10 years before applying for a Certificate of Lawfulness or claiming immunity.
2. Retrospective Planning Permission vs. Lawful Development
If development has already taken place without planning permission, the owner has two main legal routes:
A. Retrospective Planning Application
This involves applying for permission after the fact. The LPA will assess the development in line with current policies, as they would any normal application. If refused, enforcement action may follow.
B. Certificate of Lawfulness of Existing Use or Development (CLEUD)
This is a legal confirmation that a development or use is now lawful due to the passage of time—specifically, because no enforcement action has been taken within the statutory period.
To be granted a CLEUD, the development must have been:
• In existence or in use for at least 10 years by the time of application (post-April 2024)
• Not deliberately concealed or misrepresented
• Substantially complete (for building works)
3. When Does the 10-Year Clock Start?
The start of the 10-year period depends on the type of development:
A. Operational Development (Building Works)
• The 10-year clock starts on the date the works are substantially completed.
• “Substantially complete” means the building or structure is functionally and visually finished, even if minor works are outstanding.
Example: A garage built without permission and substantially completed on 1 May 2014 would have become immune from enforcement under the old 4-year rule on 1 May 2018. However, if substantial completion occurred on or after 25 April 2020, the 10-year rule now applies, and it wouldn’t be lawful until 25 April 2030 (unless a CLEUD was already granted).
B. Material Change of Use (Including Conversion to a Dwelling)
• The 10-year period starts from the date the unauthorised use commenced and has continued uninterrupted.
Example: If an outbuilding began being used as a self-contained flat in June 2015, and has been continuously occupied since, it could be lawful now under the 10-year rule—provided no enforcement was taken and the use wasn’t concealed.
C. Breach of Planning Conditions
• The clock begins from the date the condition was first breached and not complied with for the full 10 years.
Example: If a condition limited business opening hours, but the premises operated outside those hours from August 2014, and has done so continuously, the breach may now be lawful.
4. Certificates of Lawfulness: Proving the 10-Year Period
To apply for a CLEUD under Section 191 of the Town and Country Planning Act 1990, the applicant must prove, on the balance of probabilities, that the development or use has been lawful for at least 10 years, uninterrupted.
Key Evidence Includes:
• Dated photographs showing construction or use
• Council tax or business rates records
• Utility bills
• Tenancy agreements or sworn statements (statutory declarations)
• Aerial imagery
• Invoices or delivery notes from contractors
Without strong, consistent evidence, the LPA is likely to refuse the certificate.
5. Exceptions: Deliberate Concealment
A key limitation on the 10-year rule is where there has been deliberate concealment or deception.
Case Example: Welwyn Hatfield BC v SSCLG [2011]
A house was built inside a barn and disguised to avoid detection. The courts found that the developer could not claim immunity due to the intentional concealment.
In such cases, the LPA can take enforcement action even after the 10-year period, and may seek:
• An injunction
• Criminal prosecution for fraud
• Demolition or cessation of use
6. Practical Guidance: What Should You Do?
If You’re Within the 10-Year Window:
• Consider a retrospective planning application if the development is recent and aligns with planning policy.
• Don’t wait passively—start collecting evidence now.
If You’ve Reached the 10-Year Mark:
• Prepare a Certificate of Lawfulness application with full evidence.
• Pinpoint the exact date of substantial completion or commencement of use.
• Obtain statutory declarations from neighbours, tenants, or contractors.
Don’t:
• Rely on outdated advice about the 4-year rule
• Assume enforcement won’t happen simply because the LPA hasn’t acted yet
• Try to hide the development
7. Summary Table: Enforcement Periods Before and After 25 April 2024
Type of Breach / Before 25 April 2024 / After 25 April 2024
Operational development (e.g. building) / 4 years / 10 years
Change of use to single dwelling / 4 years / 10 years
All other changes of use / 10 years / 10 years
Breach of planning conditions / 10 years / 10 years
Conclusion
As of 25 April 2024, all unauthorised development in England must meet the 10-year rule to become immune from enforcement. The date of substantial completion or the commencement of use is now critical in calculating immunity, particularly where previously only 4 years were needed.
Whether applying for a retrospective permission or a Certificate of Lawfulness, success hinges on the quality of your evidence and a clear understanding of the time limits. With enforcement powers now more consistent—and stricter—planning ahead is essential.
Disclaimer: This article is for general informational purposes only and does not constitute legal or professional advice. Always consult relevant professionals and local authorities before undertaking any development or change of use.