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Retrospective Planning Permission

Retrospective planning permission is the granting of planning approval after works have started or completed.

Applying for Retrospective Planning Permission - What You Need to Know

Have you built a house extension or renovated your property without planning permission? Has there been a change of use of your property that was not authorised by the local planning department?

This guide explains what retrospective planning permission is and how to apply for it.

Have you ever dreamt of building an extension or renovating your kitchen only to discover later that you should have applied for planning permission? Perhaps you inherited a property modifications, or a change of use that were not authorised. Maybe your enthusiastic builder commenced work before all the paperwork was in place. Whatever the reason, you now find yourself in the unenviable position of having make a retrospective planning application.

Don’t panic!

While the situation is far from ideal, it is possible to obtain retrospective planning permission, but it has to be done in the right way. This comprehensive guide gives you the resources necessary to make a successful application, including why it is necessary to have it in place, how to apply for it, what to do if your application is refused and most importantly, is it worth the risk?


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What is Retrospective Planning Permission?

Imagine the scenario: you’ve completed work on a fabulous new extension only to receive a notice from the local council that says you’ve breached planning regulations. It’s a nightmare scenario but one that unfortunately, many property owners find themselves in.

Unauthorised works could include:

  • Construction of an extension or a new building in the grounds
  • Change of property use
  • Display of advertisements
  • Works to listed buildings or protected trees
  • Failure to comply with original planning consent –  for example, the design changed or the relevant planning conditions were not complied with

It’s essential to be aware of the local planning regulations, and understand when planning permission is required for various types of developments. Ignorance of planning rules is not an excuse, and property owners are responsible for ensuring compliance with planning laws.

Without planning permission the work can be labelled ‘illegal’, and you could face severe penalties. At best a steep fine or at worse, an order to demolish the unauthorised alterations.

This is where retrospective planning permission comes in. It allows property owners to seek approval for changes that have already been made to their properties, without prior consent from the local planning authority. By making a retrospective planning application, may be able to avoid legal action and ensure that your property complies with planning regulations.

Note that it’s more seeking forgiveness for what you’ve done, rather than asking for permission, as the damage has already been done! It’s a last resort for rectifying a breach of planning regulations.


Just like any other application, planning authorities consider these applications on their own merits and there is no guarantee of approval. However, if granted, the permission makes your work legal!


Why Do I Need Retrospective Planning Permission?

These are the common pitfalls:

  • Lack of Awareness – the property owner may simply be unaware of planning regulations governing their area. They embark on projects assuming that  the changes they are making are allowable, and only realise their mistake later.
  • Time Constraints and Impatience – the planning process can be protracted and time-consuming, with some applications taking weeks or even months to be approved. Tight deadlines can lead to impetuousness and  eager property owners or contractors may simply decide to proceed without waiting for permission from the planning authority.
  • Misjudgement or Oversight – they property owner may underestimate the extent of planning requirements or think that the changes fall under ‘permitted development‘.

While the process may appear straightforward, navigating the complexities of retrospective planning permission can be daunting. Property owners have to contend with legal intricacies, administrative hurdles, and the uncertainty of the outcome. Moreover, the stakes are high, with refusal of permission potentially leading to enforcement action, financial penalties, or even criminal charges.

Why Was Retrospective Planning Application Not Applied For?

There are three main reasons why you might need to apply for retrospective planning permission:

  • Omission – the build went ahead without permission being sought and you need to authorise the work
  • Selling a property –  you need to sell your house and the purchaser’s Solicitors require confirmation.
  • Enforcement Action – the local authority discovered, (or was notified by a neighbour) of, your unauthorised development and requires you to apply retrospectively. For more information read our page on enforcement action

What Are The Risks of Ignoring Retrospective Planning Permission?

It might be tempting to ignore the issue, but the risks associated with failing to address unauthorised development are significant.

Here’s what you could face:

  • Enforcement Action – local authorities have the power to take enforcement action. This could involve hefty fines, a legal order to demolish the unauthorised work, or even criminal prosecution in extreme cases.
  • Difficulty Selling Your Property – selling a property without the necessary planning permission can be difficult. The buyer’s surveyor will easily find out and potential buyers may be made aware of the legal implications. They would find it impossible to obtain a mortgage on your property.
  • Insurance – home insurance policies can be invalidated if your property has unauthorised modifications. This could leave you out of pocket leaves when you come to make a claim.

What Is The Time Limit For For Retrospective Planning Permission?

Retrospective Planning Applications do not have a strict deadline for submission. However, there are crucial factors to consider regarding timing:

  • Enforcement Action if the Local Planning Authority (LPA) is made aware of an unauthorised development and initiates enforcement action, obtaining retrospective planning permission is crucial to avoid potential penalties. Before formal action is undertaken the LPA may invite owners to submit a retrospective planning application and usually sets a deadline for submission.
  • The 4-Year and 10-Year Rules If the LPA hasn’t taken enforcement action, the unauthorised works may become lawful by virtue of the passage of time.If your unauthorised development has existed for four years (for certain developments, like house extensions or changes of use to a dwelling) or ten years (for other unauthorised development), you might be eligible to obtain a Certificate of Lawful Development instead of Retrospective Planning Permission. However, this is not guaranteed and conditions might apply.
  • In England, the 4-year rule has recently been removed although transitional provisions may apply.

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What Is The Respective Planning Application Process?

Here’s a step-by-step guide:

  1. Assessment – the LPA will assess the changes made to your property and determine whether they require retrospective planning permission.
  2. Consultation – it is essential you seek advice from an planning expert to understand the requirements and implications for retrospective applications.
  3. Application Submission -you will need to complete the application forms and submit them to your local planning authority, along with detailed plans, assessments, and a justification for the unauthorised works. This aims to demonstrate compliance with regulations and minimise any adverse consequences
  4. Consideration:  the LPA will review your application and consider factors such as the impact on the surrounding area, and compliance with local and national policies. They may choose to consult with your neighbours and other interested parties about your application. This allows them to consider potential concerns or objections to the unauthorised development.
  5. Determination of the Application – the LPA will review your application carefully, considering compliance with building regulations and the design of the development. They will then issue a decision, which could be:
  • Approval: The ideal outcome. It legalises your unauthorised development.
  • Conditional Approval: The LPA may grant approval subject to certain conditions, such as modifications to the development or additional landscaping.
  • Refusal: You will receive a written explanation outlining the reasons for the decision.

How Long Does It Take To Get Retrospective Planning Permission?

There is no fixed time. While the timeframe may resemble a standard application, several factors can influence the timeline:

  • Complexity of the Project– retrospective applications involve existing buildings or modifications. Working through the changes required to accommodate planning regulations can be challenging which can extend the timeframe.
  • Application Completeness– a well-prepared application with all the required documents simplifies the process for the Local Planning Authority (LPA). Missing information or delays in providing additional details can lead to delays.
  • Scale of the Development – minor applications, particularly those falling under householder categories benefit from faster processing times. The LPA typically has a target turnaround period of eight weeks for minor applications and 13 weeks for major developments.
  • LPA Workload and Resources: The workload of the LPA can impact the processing time. If they’re dealing with a high volume of applications, yours might take longer to be reviewed.

The LPA can request additional information or conduct consultations, which can add to the processing time. They may also grant extensions to give them time to fully consider complex issues.


What Happens if Your Retrospective Planning Application is Refused?

If your retrospective planning application is refused, you may face several consequences, including:

  • Enforcement Action: The local planning authority may require you to stop any further work and revert the property to its original state or use.
  • Legal Action: Failure to comply with planning regulations can result in legal action, including fines or even criminal charges.
  • Insurance Implications: It may be challenging to obtain insurance for unauthorised developments, and your current insurance policy may be invalidated.
  • Financial Costs: Reversing unauthorised work can be costly, and you may incur expenses for demolition or restoration.

Can I appeal A Retrospective Planning Application Decision?

If your retrospective planning application is refused, you don’t have to accept the decision. You have the right to appeal the decision to the Planning Inspectorate, an independent body that reviews planning decisions made by local authorities.


Retrospective Planning Application - Is It Worth the Risk?

While it might seem logical to ask for forgiveness rather than obtain permission beforehand, applying retrospectively is a gamble. If permission is denied, the cost of demolishing the unauthorised work can be substantial. Also any potential exemption or relief to the Community Infrastructure Levy (CIL) (a charge which can be levied by local authorities on new developments in their area) may not be possible, which could add of pounds to the total cost.

It’s always best to follow the rules and obtain planning permission before starting any construction work. 

Before You Start

  • Check if your project requires planning permission with your local authority. A Lawful Development Certificate can be obtained to formally confirm that you don’t require planning permission.
  • If required, apply for planning permission before construction begins.

Is applying for retrospective planning permission worth the risk if you already have unauthorised development?

The answer is not simple and depends on a number of factors:

  • The nature of the unauthorised development
  • The likelihood of approval, and the potential consequences of non-compliance. While obtaining retrospective permission can provide peace of mind and legal certainty, it comes with no guarantees and can entail considerable time, effort, and expense.



Retrospective planning permission offers a lifeline for property owners who have made changes to their properties without obtaining approval prior to any work being done. If you follow the correct procedures and seek professional advice, you can navigate the process and ensure compliance with planning regulations.

It is essential to weigh the potential risks and consequences before making a retrospective application and to consider alternative options for rectifying planning breaches. Compliance with planning laws is crucial to avoid legal trouble and protect the value of your property.

If you are facing planning enforcement action don’t hesitate to contact us to discuss the issues. We help you navigate the complexities of planning regulations to safeguard the future of your property.


Disclaimer: This page provides an introduction only and is not a definitive statement of the law and should therefore not be relied upon. The information above relates to England only. Policies across the rest of the UK may differ. Contact your Local Planning Authority for advice and confirmation before any works are carried out. All images used are for illustrative purposes only. Read the full disclaimer here.

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