Enforcement appeal ground (d) and immunity periods

Enforcement appeal ground (d) says that when the council issued its notice, it was already too late. No enforcement action could lawfully be taken, because the breach had become immune through the passage of time. Win on ground (d) and the notice is quashed without anyone examining whether the development was a good idea.

The difficulty is that the time limits in section 171B of the Town and Country Planning Act 1990 have been rewritten, the transitional line depends on when your breach arose, and the burden of proving continuity sits entirely with you. A landlord who assumes an old conversion is safe because it has been there "for years" is exactly the person who loses this appeal.

What ground (d) requires you to prove

Ground (d) in section 174(2) asserts that at the date the notice was issued, no enforcement action could be taken in respect of any breach of planning control constituted by the matters alleged. Three elements have to be established.

First, what the breach actually is, because the period depends on its character. Second, the date the relevant period began, which for building works is the date the development was substantially completed and for a change of use is the date the material change occurred. Third, that the use or the operation continued without a relevant break from that date until the date the notice was issued.

The standard of proof is the balance of probabilities and the burden is on you. The council does not have to disprove your case. If the inspector is left unsure whether the use ran continuously from 2012, you lose.

The periods that apply to different breaches

The historic scheme in England drew a distinction between operations and uses.

Those categories caused most of the arguments. A loft converted into a self-contained flat is a change of use to more than one dwellinghouse, so the ten-year period applied rather than the four-year one, and landlords who had counted four years from the building work found themselves six years short.

Note the exclusions. There is no immunity period for unauthorised works to a listed building, and separate regimes apply to protected trees and to advertisements. Ground (d) on a listed building case is not available on the basis of elapsed time alone.

The reform of the periods and where it bites

The Levelling-up and Regeneration Act 2023 amended section 171B so that a single ten-year period applies in England to all breaches of planning control. The amendment was brought into force by regulations made in 2024, and it applies to breaches arising on or after the relevant date, with the previous four-year periods continuing to apply to breaches that arose before it.

That transitional structure is where the work is. The question on any given case is how long the breach has existed and also whether it arose before or after the change took effect, and for operational development that turns on the date of substantial completion. Two apparently identical garden annexes can sit on opposite sides of the line.

Because the transitional provision and the exact date govern the outcome, check both against the consolidated text on legislation.gov.uk before you advise, rather than relying on a summary. The position described here is as at September 2026. Our note on immunity from enforcement and the four and ten year rules goes through the mechanics of the periods themselves in more detail.

Evidence that establishes continuity

Ground (d) is won on paper. Assertion, however sincere, carries very little weight with an inspector who has read a hundred of these.

The evidence that works is dated, independent and boring.

• Council tax records and banding history, which for a separate unit of accommodation are close to conclusive on the date it came into existence.
• Tenancy agreements in an unbroken sequence, with the deposit protection records that accompany them.
• Utility accounts in the names of successive occupiers, showing consumption rather than a standing charge.
• Bank statements showing rent received, redacted as necessary.
• Dated aerial imagery and street-level imagery, which is often the fastest way to fix the date a structure appeared.
• Statutory declarations from occupiers, neighbours, the builder or the letting agent, each dealing with a specific period rather than offering a general impression.
• Electoral roll entries and correspondence addressed to the individual unit.

A statutory declaration on its own rarely carries a ground (d) appeal, and a bundle of documents with a two-year hole in the middle rarely does either. Fill the gaps before you submit, because you will not be given a second chance to do it after the council's statement lands.

Gaps, cessation and abandonment

A break in the use can reset the clock, and this is the issue on which most ground (d) appeals turn.

Short interruptions between tenancies, a void while the property is refurbished, or a period when a room was used by a family member rather than let are usually survivable, because the question is whether the character of the use continued rather than whether the building was occupied every night. But a longer cessation with a change of circumstances is different. Where the use has been abandoned, the clock starts again when it resumes, and abandonment is judged on the physical condition of the property, the length of the gap, whether there was an intervening use, and the owner's intentions.

The practical advice is to identify every gap in your own evidence before the council does and to explain each one in the statement of case. An unexplained void invites the inspector to find that continuity is not established. An explained void, supported by the refurbishment invoices, usually does not.

Be careful with a change in the intensity or nature of the use during the period. If the property operated as a single household let for five years and then as a small house in multiple occupation, you may have two different uses and a period that started later than you think.

Concealment and the planning enforcement order

Immunity does not reward deliberate concealment. Sections 171BA to 171BC of the 1990 Act allow a local planning authority to apply to a magistrates' court for a planning enforcement order where a breach has been deliberately concealed, and an order extends the time in which enforcement action can be taken.

There is also a general principle from the Supreme Court's decision in Welwyn Hatfield Borough Council v Secretary of State for Communities and Local Government that positive deception can prevent a person from relying on the statutory immunity. The bar is deliberate deception rather than mere silence, but the line is not always where a client hopes.

So advise carefully where the history includes a building control application that described the works differently, a lawful development certificate application that was withdrawn, a letting that was never declared, or correspondence with the council that misstated the position. Raising the difficulty yourself is better than having it produced by the council in its statement.

Building the bundle

Treat the appeal as an evidential exercise from the first day.

1. Fix the start date and say what it is, with the document that proves it.
2. Produce a year-by-year schedule of occupation or operation to the date the notice was issued, cross-referenced to the documents.
3. Deal with each gap on its own terms, in the schedule rather than in a footnote.
4. Obtain statutory declarations covering the periods where documents are thin, drafted so that each declarant speaks only to what they know.
5. Address the transitional position on the time limits expressly, and state which period you say applies and why.
6. Say nothing about the planning merits unless you are also running ground (a).

Once the council replies, the questionnaire and its statement will show you which years it is attacking, and our note on the appeal questionnaire and the council's statement explains how to read it. Earlier inspector decisions on comparable facts can be used to show how continuity arguments have been approached, in the way described in our note on using appeal decisions as evidence in an application, though they are indicative rather than binding.

If the use is in fact immune, the cleaner long-term answer is a certificate of lawful existing use or development under section 191 of the 1990 Act, which settles the position on the register instead of leaving it resting on one appeal decision. Where you are also arguing the merits, the planning case belongs in a properly structured Planning Statement rather than inside the grounds.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope can draft the supporting planning documents in minutes, ready for review. Enter your postcode on PlanScope to see which reports your site is likely to need.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.