4 and 10 year rules

Understanding the Basics: What are the 4 and 10-Year Rules?

At London Extend, a common area of concern for homeowners is development that has been carried out without the necessary planning permission. Perhaps a previous owner built an extension, or you undertook work yourself without realising consent was required. This is technically known as unauthorised development, and it leaves your property vulnerable to enforcement action from your local council. If the council takes action, they can, in many cases, require you to demolish the structure or return the property to its original state—a costly and stressful ordeal.

However, the planning system recognises that it wouldn't be practical or fair to enforce against historic breaches indefinitely. This is where the 4 and 10-Year Rules come into play. These are statutory time limits, set out in Section 171B of the Town and Country Planning Act 1990, after which most types of unauthorised development become immune from enforcement action. Once this immunity is gained, the development is considered lawful from a planning perspective.

The time limits are currently categorised as follows:

• The 4-Year Rule: This applies to two specific types of breach:

  1. Operational development, which means building, engineering, or other construction works (e.g., building an extension or an outbuilding).

  2. The change of use of a building into a single dwellinghouse (e.g., converting an office or a barn into a home).

• The 10-Year Rule: This is a catch-all for every other type of planning breach. This most commonly includes:

  1. A change of use of land or buildings that doesn't involve creating a dwelling (e.g., using a residential garden as commercial storage).

  2. A breach of a planning condition attached to a previously granted permission (e.g., operating a business outside of permitted hours).

It's absolutely critical to understand which rule applies to your specific situation, as the timeframe makes a significant difference.

A Critical Update: The End of the 4-Year Rule

A major change is on the horizon that will impact homeowners across the country. The Levelling-up and Regeneration Act 2023 is set to abolish the 4-year rule. While the exact date this comes into force is subject to secondary legislation, the industry anticipates this will happen in late 2024 or early 2025. Once enacted, all planning breaches will fall under a single 10-year rule.

The good news is that this change is not retrospective. If your unauthorised works or change of use to a dwelling was substantially completed before the new law comes into effect, it will still benefit from the original 4-year rule.

This creates a window of opportunity. If your project is approaching or has just passed the four-year mark, we strongly advise you to act immediately to formalise its status. Waiting could mean you suddenly need to prove ten years of continuous existence instead of four—a much harder task.

How the Rules Apply in Practice: Real-World Scenarios

To help clarify these rules, here are some common examples we see in our work:

• Scenario 1: You built a granny annexe in your garden three years ago without planning permission, and it's been continuously occupied since. You would currently be aiming to pass the 4-year mark to gain immunity.

• Scenario 2: You converted the ground floor of your property into a small shop five years ago. Because this is a change of use not to a dwelling, it falls under the 10-year rule. You would still be liable for enforcement action.

• Scenario 3: Your planning permission for an extension had a condition stating that a specific window must be obscure-glazed to protect a neighbour's privacy. You installed clear glass instead and have had it for six years. This is a breach of condition, so the 10-year rule applies.

• Scenario 4: A previous owner converted an old office building into a single house five years ago. This falls squarely under the 4-year rule and would now be considered lawful.

Key Exceptions: When the Rules Don't Apply

It is crucial to understand that these time limits are not a guaranteed 'get out of jail free' card. There are important situations where they do not apply:

• Deliberate Concealment: If you have taken active steps to deliberately conceal the unauthorised development, the clock does not start ticking. For example, building an unauthorised basement and then landscaping over it to hide its existence would be considered concealment. The council can apply to the Magistrates' Court for a "planning enforcement order," allowing them to take action long after the normal time limits have expired.

• Listed Buildings: The 4 and 10-year rules relate only to planning control. They offer no protection whatsoever for unauthorised works carried out to a Listed Building. Listed Building Consent is a separate legal requirement, and there are no time limits on enforcement action for breaches. Councils can demand a listed building be restored to its original state decades after the work was done.

• Demolition in a Conservation Area: Similarly, the rules do not apply to the unauthorised demolition of a building within a Conservation Area.

My Development is Past the Time Limit: What's Next?

So, your extension was completed over four years ago, or you've been breaching a condition for more than ten. While the development is technically immune from enforcement, this status isn't officially recognised. The burden of proof rests entirely on you, the homeowner, to prove it.

If the council receives a complaint, or you try to sell your property, you will have no official documentation to prove the development is lawful. This can lead to intrusive investigations and seriously complicate or even halt a property sale. To solve this, you must proactively regularise the situation.

The Power of Proof: Applying for a Lawful Development Certificate

The formal way to prove that your development is immune from enforcement is by applying to your council for a Lawful Development Certificate (LDC). This is not a planning application; the council cannot consider the planning merits of the development. They can only make a purely legal decision based on one question: on the balance of probability, has the development been continuously in place for the required time period (4 or 10 years)?

To be successful, you must submit a robust application supported by clear, unambiguous evidence. This evidence could include:

• Dated photographs or aerial imagery showing the development in place.

• Signed and sworn affidavits (statutory declarations) from yourself and any other relevant parties (e.g., neighbours, builders).

• Invoices, receipts, and bank statements from contractors that prove the completion date.

• Utility bills or council tax records for the relevant period if proving a change of use.

If the council is satisfied with your evidence, they will issue the LDC. This is a legally binding document that confirms the lawfulness of your development forever, securing your property's value and providing complete peace of mind.

What if the Time Limit Hasn't Passed Yet?

If you have unauthorised works and the immunity period has not yet expired, you have a few options, each with its own risks.

• If the council is unaware: You could choose to wait for the relevant period to pass. While doing this, you should diligently collect evidence for a future LDC application. However, this is a gamble. There is always a risk the council will discover the breach before you reach the time limit and begin enforcement proceedings. Remember, you must not attempt to conceal the development during this time.

• If the council is aware: The best course of action is often to be proactive and submit a retrospective planning application. This is an application for permission for work that has already been carried out. It will be judged against the same planning policies as a normal application, and there is no guarantee of success. However, it demonstrates a willingness to resolve the issue and is often the only way forward once the council is involved.

Facing Enforcement Action? How to Use the Rules in Your Defence

Receiving an enforcement notice is a very serious matter and you must act quickly. The notice will specify a deadline by which you must appeal. If your development has been in place for the required 4 or 10 years, you have a strong basis for an appeal.

You would appeal under Ground (d), which is specifically that the time limit for taking enforcement action has passed. As with an LDC application, the success of your appeal will hinge on the quality and strength of your evidence. If your appeal is successful, the enforcement notice will be quashed.

Failing to either comply with an enforcement notice or appeal against it before the deadline is a criminal offence. This can lead to prosecution in the Magistrates' Court and potentially an unlimited fine. At London Extend, we urge anyone who has received an enforcement notice to seek professional advice immediately to understand their options.