Understanding the 4-Year Rule for Planning in Planning Law

Introduction

If you have carried out building works or changed the use of a property without the correct planning permission, you may have heard about the so-called “4-year rule”. For many years, this rule has been a crucial safeguard for property owners and developers, allowing certain unauthorised developments to become lawful over time and protecting them from costly and stressful enforcement action.

However, significant changes to planning legislation in April 2024 mean the position is no longer as straightforward. In many cases, the period required to gain immunity from enforcement action is now 10 years, not four.

In this guide, we explain:

• What the 4-year rule was and when it still applies

• How the 10-year rule now operates

• The transitional arrangements introduced in April 2024

• What evidence you need to prove lawfulness

• Whether a Certificate of Lawfulness or a retrospective application is the right route for you

If you need advice on your specific circumstances, contact our planning team today for tailored, expert support.

Understanding the 4-Year Rule and the 10-year rule

Before 25 April 2024, planning law distinguished between different types of breaches of planning control:

• 4-year rule – Applied where:

  • Building or engineering works were carried out without permission, or

  • A change of use to a single dwellinghouse took place

  If no enforcement action was taken within four years of the breach, the development became immune from enforcement.

• 10-year rule – Applied to all other breaches, including:

  • Breaches of planning conditions

  • Other material changes of use

What Changed in April 2024?

In April 2024, the Government amended planning legislation so that the 4-year rule was removed, with a 10-year enforcement period applying in all cases.

However, a transitional provision was introduced.

Transitional Arrangements – Why the Dates Matter

• If the development or change of use was substantially completed by 25 April 2024, the 4-year rule still applies

• If the development was completed on or after 26 April 2024, the 10-year rule applies

In practical terms:

• Works without planning permission completed on or after 26 April 2024 will not become lawful until 25 April 2034

It is important to stress that completion before April 2024 does not make the development lawful by default. It simply means enforcement action must be taken within the applicable time limit.

How Do I Confirm My Development Is Lawful?

If the relevant 4-year or 10-year period has passed, and you can demonstrate this with robust evidence, you can apply for a Certificate of Lawfulness of Existing Use or Development (CLEUD).

If granted, this certificate:

• Confirms the development is lawful

• Prevents future enforcement action

• Provides certainty for lenders and purchasers

• Can significantly increase the value and saleability of a property

Unlike a planning application, a Certificate of Lawfulness is not assessed against planning policy. Matters such as visual impact, sustainability, Green Belt designation or proximity to services are irrelevant.

The decision is based entirely on evidence. To quote one Planning Inspector - lawful can be awful.

Related reading:
Certificate of Lawfulness – Everything You Need To Know

What Evidence Do I Need?

When making a Certificate of Lawfulness application, it is essential to provide sufficient evidence, and planning law is clear that the onus is on the applicant to provide the evidence. Below we provide an overview of some of the evidence that may be required to support your case.

1. A sworn statement or affidavit: These are documents which are statements from people who have direct knowledge of the facts. This could include the landowner/ landlord, tenants, staff, neighbours or builders. If your case rests on statements from yourself or others, they should always be signed in the correct form, which is often in the presence of a solicitor or Commissioner of Oaths. While letters and unsworn statements can help your case, relying on them alone introduces risk. In our experience, the provision of sworn statements is recommended.

2. Council Tax or Business Rates Records: They will need to cover the relevant period and should be specifically addressed to the flat number, floor or building which is part of the application. For example, if you are looking to confirm what was originally an annexe to 1 High Street is lawfully a separate dwelling, the Council Tax records would need to show the building as a separate dwelling. Just providing Council Tax records for 1 High Street is unlikely to help your case.

3. Utility Bills: Utility bills can be vital to proving that the building has been used continuously for the 4 or 10 year period. Similar to the above, they will need to be clearly made out to the separate building (e.g. annexe).

4. Tenancy Agreements: If you have rented out the accommodation, copies of tenancy agreements can be useful. If relevant, it is important that they key information (such as names, dates and costs) on copies of the tenancy agreements and the sworn statements match each other.

5. Bank Statements: Bank statements can be used to demonstrate that rent has been paid or received for the property.

6. Building Control Records: Final Inspection Certificates from Building Control provide useful evidence that works were complete by a certain date.

7. Invoices: Copies of invoices relevant to the conversion works can also help your case.

8. Dated Photographs: To help your case, photographs need to be clearly dated.

Please note that this list is not exhaustive, and in certain circumstances, more or less information may be required. If the Council has any evidence to contradict yours, this can make things challenging.

How will the Council Assess My Application?

The Council will review your evidence and cross-check it against:

• Council Tax records

• HMO licensing databases

• Historical planning files

• Enforcement records

The legal test is whether, on the balance of probabilities, the use or development has existed continuously for the relevant time period.

Because Certificate of Lawfulness applications are not planning applications, they will not and cannot take into account more general planning considerations. The fact that a new dwelling is in the wrong place, or looks out of place is not a consideration. To quote one Planning Inspector - lawful can be awful.

While the onus is on the applicant to provide enough evidence, if the Council has no evidence to the contrary, they should approve the application. The balance of probabilities test is lower than the 'beyond reasonable doubt' used in the criminal system, but we always recommend providing as much evidence as you can.

What If My Application Is Refused?

If refused, you have the right to appeal to the Planning Inspectorate.

Officer Reports often accompany Certificate of Lawfulness applications are often invaluable, as they explain why the Council was not satisfied with your evidence. For example, it may highlight that the submitted evidence does not cover a certain timeframe, or that key evidence is missing.

For a free initial appraisal on your appeal prospects, contact our team of experienced consultants.

Certificate of Lawfulness vs Retrospective Planning Permission

If you need to regularise unauthorised works, there are two main options:

Certificate of Lawfulness

Best where:

• You meet the 4-year or 10-year rule

• You have strong supporting evidence

Advantages:

• No planning policy assessment

• No risk of refusal on design or policy grounds

Retrospective Planning Application

More appropriate where:

• Insufficient evidence exists

• The development is likely to comply with planning policy

However, Councils are often resistant to certain developments, such as:

• Annexes used as independent dwellings

• Garage conversions forming separate units

Where evidence exists, a Certificate of Lawfulness is usually the stronger and safer route.

Need Expert Advice?

Every case turns on its own facts, evidence and timing. A small error in approach can mean the difference between a lawful development and enforcement action.

At Cedar Planning, we regularly advise on:

• Certificates of Lawfulness

• 4-year and 10-year rule assessments

• Evidence strategy and sworn statements

• Appeals against refusals

Contact us today for a confidential review of your case and clear advice on the best planning route forward.