A Chartered Town Planner's honest, evidence-led answer — based on the cases we handle every week.
In our experience as Chartered Town Planners specialising in retrospective applications, around 70% of cases are approved outright, a further 10% are approved subject to minor modifications, and 20% are refused. Put simply: roughly four out of five retrospective planning applications result in some form of consent. The success rate is much higher than most homeowners expect — and there is a clear reason for that.
These figures are not a national statistic; they are our own pattern of outcomes across the retrospective casework RPE handles. They are consistent with the wider position councils report when retrospective applications are properly prepared. Around 70% of the cases we take on are granted permission as submitted. About 10% are granted after a small change negotiated with the case officer — a tweak to materials, a reduction in height, a privacy screen, a revised use restriction. The remaining 20% are refused, usually because the underlying breach is too significant to design out, the site is heavily constrained, or the council's policy position simply will not bend.
The headline takeaway: most retrospective cases that reach a properly drafted application are approvable. The biggest mistake homeowners make is assuming the council's enforcement letter means the answer is no. It usually doesn't.
The success rate looks high until you understand what these cases actually look like. Most retrospective applications fall into one of four categories — and all four have one thing in common.
Across all four categories, the underlying development is usually modest, well-intentioned and not inherently harmful. It is rarely "major development". It is rarely something that would have been refused had it been applied for in advance. The council's job, when handling a retrospective application, is to assess it as if the work had not yet been done — on its planning merits. Section 73A of the Town and Country Planning Act 1990 makes that explicit. So the question is not "should we punish you for building it?" but "would we have granted this if you had asked first?". For most of the cases that come through our door, the honest answer is yes.
The cases that end in refusal are not random. They cluster around a small number of features that planning officers find genuinely difficult to overlook.
Even within the 20% that are refused, an honest assessment up front would usually have flagged the risk. That is why the first conversation we have with every client is a free, written read on whether the case is realistically approvable. If it isn't, we say so — and we look at the alternatives (revert the works, lawful development certificate, enforcement appeal, sometimes phased withdrawal).
The single biggest driver of success is the quality of the planning statement. Councils receive thousands of self-submitted retrospective applications a year. Most of them argue from the wrong angle — usually some version of "please don't make us take it down". That is not a planning argument and it is not a basis on which a case officer can approve anything.
A planning statement prepared by a Chartered Town Planner does four things:
We see the difference clearly: cases that come to us after a self-submitted refusal often turn around at resubmission because the second application engages the policies properly for the first time.
Around one application in ten is approved subject to small changes negotiated with the case officer during determination. This is one of the most under-appreciated parts of the process. A good agent in dialogue with a sensible officer can usually find a compromise that satisfies the policy concern without requiring a refusal and resubmission. Common examples we deal with include:
None of these are catastrophic. They are the planning system finding a workable middle ground. That middle ground only exists if the application has a registered planning agent talking to the case officer in real time.
Almost always, yes. Refusing to engage with the council does not make the problem go away — it triggers a formal Enforcement Notice with an appeal window of 28 days, after which the development must be removed. A retrospective application is the structured route out, and it puts you in front of a case officer who is allowed to grant consent. With an honest assessment of whether the case is approvable, a properly drafted planning statement and a registered agent managing the conversation, the odds are roughly four to one in your favour.
If you have received an enforcement letter or are worried about works carried out without consent, the first conversation with a Chartered Town Planner is free. We will tell you, in writing, whether your case sits in the 70%, the 10% or the 20% — and what to do about it.
Retrospective planning permission is approved far more often than refused. Around 70% of cases are granted, 10% are granted after small modifications, and 20% are refused. The reason is simple: most works carried out without consent are minor, borderline or technical, not major unauthorised development — and most are approvable when the planning statement engages the right policies in the right way.
In RPE's experience, around 70% are approved as submitted, another 10% are approved with minor modifications, and 20% are refused. The combined success rate — some form of consent — is roughly 80%.
Legally, no. Section 73A of the Town and Country Planning Act 1990 requires the council to assess the application as if the work had not been carried out — on its planning merits, against the same policies. In practice, retrospective cases face slightly more scrutiny because neighbours and officers know the works already exist, but the underlying test is identical.
Yes. You can lodge a Section 78 appeal with the Planning Inspectorate within six months of the refusal date. We assess every refused case for appeal merit before recommending it — appeals are slow and expensive, and a properly resubmitted application is usually a faster route where there is room for one.
Most retrospective applications are determined within 8 weeks of validation, in line with the standard statutory target. Larger or more complex cases may take 13 weeks. The clock starts the day the council validates the submission, not the day you send it.
Worried your case sits in the 20%? A Chartered Town Planner will give you an honest, written assessment before you spend a penny. Get a free assessment →
Talk to a Chartered Town Planner today — the first conversation is free.