Documents for a retrospective application

A retrospective planning application is made under section 73A of the Town and Country Planning Act 1990, which allows permission to be granted for development already carried out, for a use already begun, or for works done without complying with a condition. The retrospective planning application documents are the same as for an ordinary application, with three differences: the drawings describe what is actually there, the planning case has to deal with harm the council can already see, and the whole thing may be running against an enforcement clock.

That last point changes the strategy more than the paperwork. Find out whether a notice has been issued before you decide what to submit.

How the application works

Procedurally it is an ordinary application. You apply to the local planning authority on the standard form, pay the fee under the current fee regulations, and the authority consults, publicises and determines it in the normal way. Fees are indexed annually, so check the current schedule rather than a figure from a previous year.

Two differences are worth knowing. The description of development should make clear that the works have been carried out or the use has begun, because a description written in the future tense invites a later argument about what was permitted. And the decision, if favourable, regularises what exists from the date of the permission, so a grant does not retrospectively make past breaches lawful for all purposes.

The application also has no effect on any separate regime. Building regulations, listed building consent, protected species licensing and party wall obligations are unaffected by a planning permission granted after the event.

As-built drawings and survey accuracy

This is where most retrospective applications fail, and the failure is avoidable.

Measure what is there. Not what was drawn, not what was approved on an earlier application, and not what the builder said they built. Commission a measured survey and produce drawings showing actual dimensions, actual levels, actual positions relative to boundaries, and actual materials.

• Existing and as-built plans and elevations at the same scale, with dimensions annotated.
• A site plan with the structure dimensioned to each boundary.
• Levels, including finished floor level and ridge height relative to a fixed datum, where height is in issue.
• Sections where eaves height or the relationship to a neighbour's window matters.
• Photographs from each neighbouring boundary, dated.
• A materials schedule describing what was actually used.

Accuracy is not a courtesy here. If your drawing shows the structure 2.1 metres from the boundary and the officer's tape says 1.7 metres, the application loses credibility on every other point. Inspectors treat an inaccurate as-built drawing as a reason to prefer the council's evidence throughout.

Where the breach is dimensional, state the breach yourself in figures. An application that says the eaves are 2.6 metres where 2.5 metres was permitted is treated very differently from one that hopes nobody measures.

Addressing harm that is already visible

An ordinary application argues about predicted effects. A retrospective one argues about effects the officer, the neighbours and the committee can go and look at. That cuts both ways.

The advantage is evidence. You can photograph the actual relationship between the structure and the neighbour's window, measure the actual overshadowing, and record the actual noise from the plant that was installed. Predicted harm that has not materialised is a point worth making with measurements rather than assertions.

The disadvantage is that complaints already exist. Deal with them in the statement rather than waiting for the consultation responses. Name the issue, set out the evidence, and offer mitigation: an obscure-glazed window, a reduced ridge, a screen, a fence, a revised plant specification, acoustic enclosure, a change of hours.

Where the works have already affected a protected species the position is more serious. Works that damaged or destroyed a bat roost may be an offence regardless of the planning outcome, and a planning permission does not cure it. Our note on a dwelling containing a known bat roost sets out the survey and licensing route. Survey work and any mitigation licence legally require a suitably licensed ecologist under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017, and a draft report is a starting point for that professional rather than a substitute.

Running alongside enforcement

Section 70C of the 1990 Act allows an authority to decline to determine an application for planning permission for development that is the subject of a pre-existing enforcement notice. That is why the order of events matters so much. Applying before a notice is issued preserves your options. Applying afterwards may leave the appeal as the only forum.

Time limits also matter. Enforcement limits in England were extended by the Levelling-up and Regeneration Act 2023, and the limits that apply depend on when the breach occurred and the date the change took effect. Where works or a use may already be immune, a certificate of lawfulness under section 191 is a better route than a retrospective application, because it establishes lawfulness rather than asking for a fresh permission.

Conditions on completed works

A permission granted after the event still carries conditions, and some of them are harder to live with than people expect.

Expect conditions requiring works to be altered or completed within a stated period, for example a window to be obscure-glazed, a roof light to be fitted with a restrictor, or a boundary screen to be installed. Expect a materials condition where the finish is part of the objection, and a landscaping condition where planting is the mitigation.

Where the use is the breach, expect conditions limiting hours, deliveries, numbers or the extent of the premises used, and in some cases a personal condition tying the use to the current occupier.

Read each condition against what is physically possible before you accept the decision. A condition requiring something that cannot be built on the structure as it stands is a condition you will breach, and the appeal window closes quickly.

The submission pack

1. Application form completed as development already carried out, with the correct ownership certificate and notice to any other owner.
2. As-built measured drawings and a dimensioned site plan.
3. Dated photographs from each affected boundary.
4. A planning statement addressing policy, the harm alleged and the mitigation offered.
5. Technical notes where the breach raises a specific issue: drainage for an unapproved hard surface, acoustic data for installed plant, structural information for a building near a sewer or in poor ground.
6. Ecology or arboricultural information where vegetation or habitat was affected.
7. A schedule of the conditions you are content with.

A garden building is the commonest version of all this. If yours is a pool building or similar outbuilding, the evidence expected for a swimming pool building in a rear garden is a good guide to the technical material that gets asked for. You can also browse the report types to see which assessments a particular breach is likely to trigger.

And resolve the measurements first. Every other part of the case rests on the drawing being right.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. A Lawful Development Certificate is the only formal way to confirm that existing works or uses are lawful. PlanScope produces AI-assisted draft reports for planning applications, and reports should be reviewed before submission. PlanScope does not guarantee planning approval.