Planning enforcement is very stressful. Having spent your life savings on a new extension or some other development, the last thing you want is to get a letter from the council’s planning enforcement team requiring that it be pulled down. It doesn’t help that communications from planning enforcement tend to be formal and intimidating.
Some councils are more active in planning enforcement than others. Unfortunately, Hillingdon is one of the councils that is quick to take action. According to government data, the council served 49 enforcement notices in the year ending September 2025, placing it among the councils with the highest number of notices issued nationally.
It is easy to fall foul of planning enforcement, even if you try and do everything by the book – you (or your builders) make small changes as you go through the build, or perhaps there is a genuine mistake or miscommunication.
Just Planning receives a lot of enquiries each year from homeowners and developers in the borough who have found themselves subject to an enforcement investigation or, worse still, a formal enforcement notice.
This article explains what planning enforcement in Hillingdon typically involves, how enforcement action usually starts, and what options you have (including how to appeal).
What is planning enforcement?
Planning enforcement is the process by which a council investigates and takes action against development it believes does not have planning permission or does not comply with an approved permission.
The most obvious breaches are where a development is carried out without permission at all, or where something is built that doesn’t quite match an approval. It also includes cases where a development was assumed to be permitted development, but it isn’t for some reason (flats don’t have permitted development rights at all, for example, and some houses lose their rights). Finally, planning enforcement targets changes or use and situations where a planning condition has not been complied with.
It is important to remember that you have not committed an offence by being in breach of planning control. You only commit an offence if the council serves an enforcement notice, that notice takes effect and you do not do what it says. Up to that point, you should not feel that you have done something wrong and you should not feel pressurised to reverse your development immediately.
How enforcement action usually starts
Though Hillingdon is a fairly aggressive council when it comes to enforcement action, its officers do not go looking for trouble – the planners do not usually check if developments have been carried out correctly and planning conditions respected. They don’t do routine reviews of development activity in an area. Most of its enforcement investigations are triggered by complaints from neighbours, so always keep them onside as best you can!
In many cases, the first contact from the council is not an enforcement notice, but an initial letter or a request for information (known as a Planning Contravention Notice, or PCN). This stage is often exploratory, allowing officers to establish what works have been carried out and whether planning permission was required. You must respond to any PCN within the time they give you and you must respond honestly.
It is important not to assume, at this stage, that formal action will necessarily follow. Much depends on the nature of the development and whether it can be regularised.
Work with your case officer
The enforcement officers in Hillingdon are not out to get you. They are not there to judge or to make your life difficult. They are just doing their jobs. So it is best not to get angry or aggressive, or to bury your head in the sand, ignore their communications and hope that this will all go away.
It is generally best to speak to your case officer, invite them out on site and get their honest advice on whether they think there is a breach, how serious they think it is and how best it may be resolved.
Hillingdon can be quick to issue an enforcement notice where they identify a breach – they are often not keen to enter in to long drawn out negotiations and discussions. It can therefore be important to act quickly once you are aware of an issue. Often the best course of action (if you have not yet received an enforcement notice) is to submit a retrospective planning application (but make sure to get professional advice first).
The (dreaded) enforcement notice
Not all enforcement letters are the same, and it is important to understand the distinctions between them.
Some letters are informal requests for information or clarification. Others may take the form of a planning contravention notice, which requires specific questions to be answered within a set period.
A formal enforcement notice is more serious, as it sets out the alleged breach, the steps required to remedy it, and the timescale for compliance.
Understanding what type of notice has been issued is critical, as the rights of appeal and the relevant time limits differ.
Never ignore an enforcement notice
The most important message is that you should never ignore an enforcement notice.
If you do, it takes effect and it becomes much more difficult to challenge. If you receive a notice, seek out professional advice immediately.
Can enforcement action be appealed?
A formal enforcement notice usually carries a right of appeal, but strict deadlines apply. Missing an appeal deadline can remove that right entirely, so timing is important.
The grounds of appeal in enforcement cases are different from those that apply to planning refusals. An enforcement appeal may involve arguments about whether planning permission is required at all, whether the alleged breach has been correctly identified, or whether the steps required by the notice are reasonable.
Each case turns on its own facts, and enforcement appeals need to be approached carefully and methodically. It is very important to obtain professional advice, ideally from a chartered town planner.
Can enforcement problems be solved without an appeal?
It is usual to appeal an enforcement notice, because otherwise it takes effect and you are legally required to do what it says.
We have sometimes been able to persuade councils to withdraw an enforcement notice, but usually only after an appeal has been submitted.
For more information on planning enforcement, check out our dedicated enforcement page.
Martin Gaine’s book, How to Get Planning Permission: An Insider’s Secrets, also has a chapter on planning enforcement.
