4-Year vs 10-Year Planning Enforcement Rule: Pre & Post 25 April 2024
For decades, Section 171B of the Town and Country Planning Act 1990 divided planning breaches in England into two separate time limits: 4 years for operational building works and change of use to a single dwellinghouse, and 10 years for all other changes of use (such as HMOs or commercial uses) and breaches of planning conditions.
Under Section 115 of the Levelling-up and Regeneration Act 2023, brought into force on 25 April 2024 by the Planning Act 2008 (Commencement No. 8) and Levelling-up and Regeneration Act 2023 (Commencement No. 4 and Transitional Provisions) Regulations 2024 (SI 2024/452), the 4-year rule was abolished in England. However, crucial transitional rules protect works completed before 25 April 2024.
| Type of Unauthorised Planning Breach | Completed / Occurred BEFORE 25 April 2024 (England) | Completed / Occurred ON OR AFTER 25 April 2024 (England) | Rule in Wales & Scotland |
|---|---|---|---|
| Building Operations (Extensions, Loft Conversions, Outbuildings, New Houses) | 4 Years from 'Substantial Completion' | 10 Years from 'Substantial Completion' | 4 Years from Substantial Completion |
| Change of Use of Any Building to a Single Dwellinghouse (Class C3) | 4 Years of continuous residential use | 10 Years of continuous residential use | 4 Years of continuous residential use |
| Change of Use to an HMO (Class C4 / Sui Generis) or Commercial Use | 10 Years of continuous use | 10 Years of continuous use | 10 Years of continuous use |
| Breach of a Planning Condition (Including Agricultural Occupancy Conditions) | 10 Years of continuous breach | 10 Years of continuous breach | 10 Years of continuous breach |
| Unauthorized Works to a Listed Building (Section 9 Listed Buildings Act 1990) | No Time Limit (Criminal offence & permanent enforcement) | No Time Limit (Criminal offence & permanent enforcement) | No Time Limit |
How the 25 April 2024 Transitional Rules Work in Practice
Regulation 5 of SI 2024/452 establishes a bright-line cutoff date of 25 April 2024 for England:
• Scenario A (Pre-25 April 2024 Completion): Suppose a homeowner built a rear extension or converted a garage into a self-contained annex without planning permission, and the building works were 'substantially completed' on 10 March 2024. Because substantial completion occurred BEFORE 25 April 2024, it remains governed by the legacy 4-year rule—meaning it becomes immune from planning enforcement on 10 March 2028.
• Scenario B (Post-25 April 2024 Completion): Suppose the same extension was started in February 2024, but the roof, windows, and plastering were not substantially completed until 15 May 2024. Because substantial completion occurred ON OR AFTER 25 April 2024, it falls under the new 10-year rule and will not achieve enforcement immunity until 15 May 2034.
Following the famous Supreme Court ruling in Welwyn Hatfield BC v SSCLG [2011] (where a builder hid a house inside a hay barn for 4 years), Parliament enacted Sections 171BA–171BC of the TCPA 1990. Where a person deliberately conceals a planning breach, the council can obtain a Planning Enforcement Order within 6 months of discovering the breach, regardless of how many decades have passed. Furthermore, unauthorised works to a Listed Building are a criminal offence with no time limit for enforcement ever.
Temporary Enforcement Stop Notices Extended to 56 Days
Alongside abolishing the 4-year rule, the Levelling-up and Regeneration Act 2023 also strengthened council enforcement powers across England:
1. Temporary Stop Notices (Section 171E): Local Planning Authorities can now issue a Temporary Stop Notice halting unauthorized building works on site for up to 56 days (doubled from the old 28-day limit) while they investigate.
2. Enforcement Warning Notices (Section 172ZA): Councils can now serve a formal 'Enforcement Warning Notice' inviting a landowner to submit a retrospective planning application within a specified window before full enforcement proceedings are launched.
3. Higher Fines for Non-Compliance: Unlimited fines apply in the courts for ignoring an effective Enforcement Notice or Breach of Condition Notice.
Checklist: What to Do If Your Property Has Unauthorised Works
If you are buying or selling a house with an unpermitted extension, loft conversion, or change of use, take these steps: