Not all planning decisions are fair and you should never just accept refusal of planning permission. Sometimes the council is right and your application deserved to be refused, but often the council has got it wrong and the decision can be challenged.
London Borough of Hillingdon fought 114 appeals in 2025 and lost about 36% of them (according to government statistics). You might find it disheartening that they won two-thirds of their appeals, but it suggests that the council is making a lot of questionable decisions. If you have been refused planning permission for the extension of your dreams or a new house for your family, isn’t a one-in-three chance of getting it over turned worth taking?
In reality, of course, the true chances of success depend on the individual circumstances of each case. We get a couple of dozen emails each day from prospective clients attaching a refusal and asking whether it is worth appealing.
Lots of those enquiries are from Hillingdon – it is one of our busiest boroughs. We provide free advice to each enquirer on their chance of success at appeal and we never take on a case that we don’t think we can win.
This article looks at when a planning appeal in Hillingdon may be worth pursuing, when it may not and how to tell the difference.
I’ve been refused permission – what now?
The first thing to do is to take a close look at your reasons for refusal and try to understand fully why your application was refused. Clients often come to use with a refusal and have misinterpreted the council’s concerns.
It is never the case that an application is refused ‘because our neighbours objected’ or because ‘a local councillor got involved’ – there are always hard planning reasons for a refusal.
To fully understand the council’s reasoning, check out the officer’s report. The case officers in Hillingdon always write a detailed report which is uploaded to their planning portal when the decision is made. It provides a wealth of information on how the council reached their decision.
Hillingdon’s Local Plan policies
When it comes to householder extensions and small development projects, Hillingdon has much stricter planning policies than almost any other council in London. Whereas most councils will have some general guidance set out in Supplementary Planning Documents, Hillingdon has detailed, specific requirements set out in its core planning policies (its Local Plan).
The policies include very specific requirements relating to the height, depth and width of extensions, distances from boundaries and the materials you must use.
If you (or your agent) didn’t read and understand those policies before you submitted your application, that might explain your refusal.
Justifying an exception to their policies
One mistake applications make is failing to read and understand Hillingdon’s policies before they apply. But an equally bad mistake others make is reading them carefully and sticking to their requirements no matter what!
Planning policies are important, but they can be set aside where it can be justified. For example, there is no need to set your side extension back one metre from the front if most other houses on your street have side extensions that have not been set back – it makes more sense that you match your neighbours than strictly follow the council’s general policies.
When to appeal
You should consider an appeal when you have read and understand the Local Plan policies, have read and understood the council’s decision and officer’s report and have decided that the council’s decision was not fair.
If you think that the council had a point and that you could make chances to your application with a chance of getting approved second time round, you should resubmit your application rather than appealing.
What a planning appeal actually involves
A planning appeal is made to the Planning Inspectorate, rather than to the council that refused the application. An independent inspector reviews the proposal, the council’s reasons for refusal and any representations that have been made.
Most householder appeals are decided through written representations. This means the decision is based on the submitted documents, plans and statements, rather than on a hearing or public inquiry. The inspector will normally visit the site, but there is no requirement for the applicant to attend.
The appeal process is not an opportunity to redesign a scheme from scratch. The inspector considers the proposal that was refused, and assesses whether the council’s decision was justified when measured against planning policy and the actual impacts of the development.
In our experience, appeals in Hillingdon are often worth considering where the refusal sticks rigidly to the council’s Local Plan policies rather than taking account of other considerations, such as the diverse character of the area of existing developments nearby.
In some of our recent appeal decisions in Hillingdon, we have successfully argued that proposals represent good design even if they do not strictly comply with Local Plan policies. In one case in Uxbridge, planning permission was granted for a new dwelling following refusal on character grounds. In another decision issued the same week, an appeal relating to side and rear extensions in Ickenham was allowed, despite concerns about the effect on a conservation area.
When an appeal in Hillingdon is often worth considering
This commonly includes cases where the council refers to:
- harm to character or appearance, without explaining the practical effect,
- concerns about bulk or dominance that are not supported by a detailed assessment,
- loss of spacing or subordination that is asserted rather than demonstrated.
In these situations, an appeal allows those concerns to be examined more closely. Inspectors will often look carefully at scale, proportions and context, rather than relying on generalised descriptions.
Appeals may also be worth pursuing where a revised scheme has been submitted to address earlier concerns, but the subsequent refusal does not meaningfully engage with the changes that have been made.
Where the impact of an extension is modest and sits comfortably within the existing pattern of development, an appeal may provide a more balanced assessment of whether refusal was justified.
When an appeal may be less likely to succeed
Not all refusals are good candidates for appeal. An appeal may be less likely to succeed where a proposal clearly conflicts with established planning principles, or where the impacts are obvious and significant.
Examples include:
- extensions that result in severe loss of light or outlook to neighbouring properties,
- proposals that substantially alter the form or scale of a building in a way that is clearly out of keeping,
- development in sensitive locations where strong policy constraints apply.
In these cases, revising the proposal or exploring alternative options may be more productive than appealing. Don’t forget that our team of chartered town planners provide free advice on your chances of success at appeal.
What about enforcement action?
If enforcement action has been taken, the position is more time-sensitive. Enforcement notices are subject to strict appeal deadlines, and the grounds of appeal are different from those applying to planning refusals.
In some cases, it may be possible to appeal the enforcement notice, submit a planning application, or do both. Early advice is particularly important in these situations.
Above all, never ignore a planning enforcement notice.
For more on planning enforcement in Hillingdon, check our our recent article here.
Taking an early, realistic view
Whether an appeal is worth pursuing in Hillingdon depends on the specific facts of the case. Two refusals that look similar on paper can have very different prospects when examined more closely.
An early review can help clarify whether the council’s reasons for refusal are likely to withstand independent scrutiny, or whether an alternative approach would be more sensible.
If you are unsure whether an appeal is worth pursuing, we are happy to give an initial view.
For more information about planning appeals in Hillingdon, see our page on planning appeals in the London Borough of Hillingdon and our recent article about why planning applications for extensions are frequently refused in the borough.
