Retrospective appeals when the work is already built
The council assesses a retrospective application as if nothing had been built. What changes is your room for manoeuvre once an enforcement notice has been issued.
A retrospective planning appeal starts from a retrospective application, and the application itself is made under section 73A of the Town and Country Planning Act 1990. That section allows permission to be sought for development already carried out, for development carried out without complying with a condition, and for a use already started. The council decides it on the same planning merits it would have applied before you built, and if it refuses, you appeal in the ordinary way.
The thing most householders get wrong is the order of events. If the council has already issued an enforcement notice, your options narrow sharply, and in some cases the retrospective route closes altogether. So the first question is not whether the extension is acceptable. It is what the council has already done.
How a retrospective application is decided
The officer assesses the development as though it were a proposal. Same local plan policies, same national framework, same material considerations, same neighbour consultation, same 21 day publicity period. A householder scheme carries the usual eight week determination period.
Two differences in practice. The description of development is written in the past tense, which affects how you draft it, and the drawings have to show what exists rather than what was approved. Measure what was built, including any variation from the original drawings, and submit as-built plans. Submitting the original approved drawings for a building that was constructed differently is the fastest route to a refusal and, later, to an enforcement notice you cannot answer.
The Planning Statement should deal with the breach head on. Explain what was built, why it differs from what was permitted or why nothing was permitted, and then make the planning case. Officers are used to this and are not hostile to it. Evasiveness in the covering documents, though, colours everything that follows.
Whether the building being finished affects the outcome
Legally, no. The fact that the structure exists is not a material consideration in favour of permission, and an inspector will assess the harm as if the land were still clear. Personal circumstances, the cost of removal and the effort already spent carry very little weight.
In practice there is one real consequence, and it runs the other way. A built structure makes the harm visible. A neighbour who writes in saying the extension blocks their kitchen window is describing something an officer can stand in front of, and an inspector can see it on the site visit. Where the objection is about overlooking or an overbearing effect, that visibility tends to strengthen the objection rather than weaken it, which is covered in our note on neighbour amenity refusals: overlooking and overbearing.
One point in your favour. A development that has stood for a period without complaint, in a street where similar forms exist, gives you a straightforward argument about the character of the area. Photograph the comparators and give their addresses.
Running an application alongside an enforcement notice
This is where the sequence matters. Section 70C of the 1990 Act allows a local planning authority to decline to determine a retrospective application where an enforcement notice has been issued in respect of the same, or substantially the same, matters. It is a discretion, not a duty, but authorities use it.
The result is that a notice can shut the retrospective door. And section 174 limits the matching move on the appeal side: the ground that permission ought to be granted is not available on an enforcement notice appeal where that notice was issued while a related application was already pending and undetermined. The two provisions together are designed to stop the same argument being run twice.
| Where you are | Route available | Deadline |
|---|---|---|
| No notice issued | Application under section 73A, then appeal if refused | Householder appeal within 12 weeks of the decision |
| Notice issued, no application made | Appeal the notice, including on the ground that permission ought to be granted | Before the date the notice takes effect |
| Notice issued while an application was pending | Appeal the notice, but that ground may be unavailable | Before the notice takes effect |
| Application refused, no notice | Appeal the refusal on the planning merits | Householder appeal within 12 weeks |
| Notice taken effect, not complied with | Compliance, or prosecution follows | Steps and period stated in the notice |
Read the notice carefully for three things: the alleged breach, the steps required, and the period for compliance. Diarise the date it takes effect, because missing the appeal deadline on an enforcement notice is not something that can be put right.
If you are still at the application stage and the officer's view is clearly negative, withdrawing an application before refusal and resubmitting a smaller scheme is sometimes the better move, since a refusal gives the council a reason to serve a notice.
The deemed application and its cost
When you appeal an enforcement notice on the ground that permission ought to be granted, a planning application is deemed to have been made for the development described in the notice. The Planning Inspectorate considers it alongside the appeal and can grant permission for all or part of what was built.
A fee is payable for that deemed application, set by the fees regulations. Those figures are indexed and have been uplifted more than once, so check the current fee schedule on the Planning Portal rather than relying on an older figure. The fee is payable on top of your own costs, and if you do not pay it the ground falls away.
Also worth knowing: the enforcement notice remains in force while the appeal is pending but its effect is suspended, so you do not have to demolish anything during the appeal. The steps only become enforceable if the appeal fails.
Site visits where the development is visible
On a householder appeal, the inspector usually carries out an unaccompanied visit if everything can be seen from public land, and an accompanied one where internal or rear access is needed. For a built scheme, access is normally needed, so expect an accompanied visit with the council officer present.
Prepare for it practically. Clear access to the rear. Have the as-built drawings and a tape measure available. Keep the conversation to pointing out what the inspector asks to see, because the visit is not a hearing and arguing the case at it is unhelpful. If a neighbour's property is central to the objection, say in your appeal statement that a view from their garden would assist, so the inspector can arrange it.
Amending what has been built
Where the breach is a departure from an approved scheme rather than an unauthorised building, two lighter routes exist. A non-material amendment application under section 96A of the 1990 Act handles small differences, such as a window position or a change of facing material. An application under section 73 varies a condition, including the condition that ties the permission to the approved drawings, which covers larger but still modest departures.
An illustrative example. A rear extension approved at 3 metres deep is built at 3.4 metres with the roof pitch altered. A section 73 application to substitute the as-built drawings, supported by a short daylight check against the neighbour's rear window, is a cleaner and quicker route than a full retrospective application, and the fee is lower. This example is illustrative and whether the change is capable of being handled under section 73 depends on its scale.
Physical amendment is the third route. Cutting back a flank wall, reducing a roof height, obscuring and fixing a side window, or removing a balustrade can turn an unacceptable scheme into an acceptable one. Offer it in writing before the decision rather than at appeal, because an officer who can recommend approval subject to alterations will usually do so.
Where removal is the realistic outcome
Sometimes it is. A structure in a position that cannot be made acceptable, on protected open land, or in front of the building line in a conservation area, will not be rescued by a well written statement. Recognising that early saves money.
If removal is where you are heading, two things reduce the damage. Negotiate the compliance period: enforcement notices commonly give a short window, and officers will often extend it to allow an orderly demolition, particularly where you have engaged. And consider whether a reduced scheme can be submitted and permitted before the notice bites, so you demolish once rather than twice.
Then there is the time limit question. Immunity from enforcement depends on how long the breach has subsisted, and the periods in England were changed by the Levelling-up and Regeneration Act 2023, with transitional rules depending on when the breach took place. A lawful development certificate under section 191 is the only way to confirm immunity formally, and the evidence burden sits with you. If you think you may already be immune, take advice before you volunteer a retrospective application, because the application itself tells the council what you have done.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. If you are putting the paperwork together, the PlanScope report index shows which supporting documents each type of application usually needs.
PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
Does the council have to consider a retrospective application?
Not always. Section 70C of the Town and Country Planning Act 1990 lets a local planning authority decline to determine a retrospective application where an enforcement notice has already been issued for the same or substantially the same matters. It is a discretion rather than a duty, but authorities do use it, which is why the order of events matters more than the merits.
Does the fact that I have already built it help my case?
No. The structure existing is not a material consideration in favour of permission, and an inspector assesses the harm as if the land were still clear. Cost of removal and personal circumstances carry little weight. The one practical effect runs against you: visible harm is easier for an objector to describe and for an inspector to see on site.
How long do I have to appeal?
For a refused householder application the appeal must be made within 12 weeks of the decision. For an enforcement notice the appeal must be made before the date the notice takes effect, which is stated on the notice. That enforcement deadline cannot be extended, so diarise it the day the notice arrives rather than waiting for advice.
What is the deemed application on an enforcement appeal?
If you appeal an enforcement notice on the ground that permission ought to be granted, a planning application is treated as having been made for the development described in the notice, and the inspector can grant permission for all or part of it. A fee set by the fees regulations is payable, those figures are indexed, and non-payment loses you the ground.
Can I just amend what was built instead?
Often, where the breach is a departure from an approved scheme rather than unauthorised development. A non-material amendment under section 96A covers small differences such as a window position or facing material, and an application under section 73 can substitute the as-built drawings. Physical alteration, offered in writing before the decision, is the third route and frequently the quickest.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.