Enforcement appeal grounds (b) and (c) compared

An appeal on ground (b) tells the inspector that the council has described something that never happened. An appeal on ground (c) accepts the description and says the thing described was never a breach of planning control. Both sit in section 174(2) of the Town and Country Planning Act 1990, both go to the same inspector, and choosing between enforcement appeal ground b or c is a question about whether your case is about facts or about law. Get that wrong and a winnable appeal turns into a costs risk.

The distinction matters most to landlords and small investors, because the notices they receive usually allege an unauthorised change of use, an unauthorised subdivision or works carried out without consent. Those are exactly the allegations where the facts and the law pull apart.

What the two grounds actually say

Section 174(2) lists seven grounds, lettered (a) to (g). Three of them attack the allegation itself.

Ground (a), by contrast, concedes the breach and asks for permission to be granted. It sits on a different footing because pleading it creates a deemed planning application, with a fee set by the fees regulations in force at the time, so check the current schedule before you tick the box.

The burden on grounds (b) and (c) rests with you. The council does not have to prove its allegation to a criminal standard. You have to satisfy the inspector, on the balance of probabilities, that your version is right.

Ground (b) is an argument about what happened

Ground (b) is narrow and literal. It attacks the words of the allegation as the council drafted them, so the first task is always to read the allegation slowly and decide which part of it is untrue.

Common ground (b) cases include a notice alleging the erection of a building when what exists is an extension to an existing one, a notice alleging use as three self-contained flats when the property operates as a single house in multiple occupation with shared facilities, a notice alleging the formation of a hardstanding that was laid decades before the date given, and a notice describing a material change of use to a different use altogether.

The risk is that ground (b) succeeds on the narrow point and achieves nothing. Section 176(1) of the 1990 Act lets the inspector correct any defect, error or misdescription in the notice, or vary its terms, provided that no injustice is caused to you or to the council. A misdescribed allegation is often corrected rather than quashed. So a ground (b) case built on a typo is usually wasted effort, while a ground (b) case built on the wrong unit of occupation or the wrong physical works can win outright.

Ground (c) is an argument about law

Ground (c) says the matters happened and were lawful all along. It is the ground you use when the works or the use never needed permission, and it turns on the definition of development in section 55 of the 1990 Act and on the permitted development rights in the General Permitted Development Order 2015.

The arguments that usually run under ground (c) are that the works fall within Schedule 2 of the Order and so are granted permission by it, that the change of use was within a single use class under the Use Classes Order 1987 as amended, that the activity is not development at all because it is neither building works nor a material change of use, that the intensification complained of has not reached the point of materiality, or that an existing planning permission already authorises what has been done.

Materiality is where most ground (c) appeals are actually decided. A change of use only needs permission if it is material, and whether letting rooms in a house tips a C3 dwellinghouse into a C4 small house in multiple occupation or into a sui generis larger HMO depends on the number of occupiers, the degree of shared living and the effect on the character of the use. That is a matter of fact and degree for the inspector, which is why ground (c) appeals are argued with floor plans, tenancy documents and occupancy history rather than with policy.

An Article 4 direction removing the relevant permitted development right or the relevant C3 to C4 change will defeat a ground (c) case built on it. Check the direction, its date and its geographic extent before you plead.

The evidence each ground needs

Ground (b) needs evidence about events and dates. Ground (c) needs evidence about the character and extent of what exists. In practice the bundles look different.

For ground (b), gather dated aerial imagery, historical council tax or rating records, utility account histories, invoices and dated photographs, plus a statutory declaration from someone with direct knowledge. Anything that fixes a date or disproves an event earns its place.

For ground (c), gather measured plans of the property as it is, room-by-room schedules showing which facilities are shared, tenancy agreements, the planning history of the site including any prior approvals, and the text of the permitted development class you are relying on with each limitation addressed in turn. Inspectors work through class conditions methodically, and a submission that skips A.1(f) or the equivalent limitation invites the same treatment as a silence.

Both grounds benefit from the same discipline you would apply when reading reasons for refusal before deciding to appeal: work out what the decision-maker has to be persuaded of, then build only the evidence that does that job.

Pleading both without contradicting yourself

You can plead more than one ground, and often you should. But ground (b) and ground (c) can read as inconsistent if you are careless, because one says the matters did not occur and the other says they did occur and were lawful.

The safe way to plead both is to keep them strictly conditional and to keep the sequence visible. Deny the allegation as drafted under ground (b), identify precisely which element is denied, then say that if the inspector finds the matters did occur as alleged, ground (c) applies for the reasons given. Never let the two grounds share a single narrative paragraph.

Where the inconsistency becomes a real problem is in the witness evidence. A declaration that describes a property as three flats while the ground (b) case denies subdivision will be read against you. Draft the factual evidence once, carefully, and make both grounds sit on top of it rather than on top of each other.

Watch the costs exposure too. An unreasonable or hopeless ground that puts the council to unnecessary work can attract an application for costs, and inspectors say so in decisions about enforcement appeals. Drop a ground you cannot evidence rather than carry it for appearances.

What winning actually achieves

If ground (b) succeeds in full, the notice is quashed because the allegation is not made out. If it succeeds in part, expect a correction under section 176 and then a decision on your remaining grounds.

If ground (c) succeeds, the notice is quashed and the position is that no planning permission was needed. That is a better outcome than success on the planning merits under ground (a), which grants permission for a breach rather than confirming there was none. It is not, though, the same as a formal confirmation of lawfulness for the future. A certificate of lawfulness under section 191 of the 1990 Act remains the only way to put the status of an existing use or operation beyond argument, and an appeal decision binds the parties on that notice rather than settling the site for all purposes.

Success on grounds (f) or (g) leaves the notice standing with lesser steps or a longer compliance period, which is a different objective entirely. Decide which outcome you are actually buying before you draft.

Filling in the form without narrowing your case

The appeal form asks you to tick the grounds and to give full particulars of each. A short discipline at that stage saves trouble later.

1. Tick every ground you can evidence, at the point of submission, because adding a ground later is at the inspector's discretion and may be refused.
2. Write the particulars for each ground under its own heading, with its own facts, its own documents and its own conclusion.
3. State the date the notice was served and the date it takes effect on the front page, because an appeal must be made before the notice takes effect.
4. Keep the planning merits out of grounds (b) and (c) altogether.

When the council replies, its case will arrive with the questionnaire and its own statement, and the shape of that response tells you which of your grounds it is most worried about. The way the appeal questionnaire and the council's statement are put together is worth understanding before you finalise your own. If you are also running a ground (a) case, the planning argument belongs in a properly structured Planning Statement rather than scattered through the grounds, and earlier inspector decisions on comparable allegations can be cited the same way you would when using appeal decisions as evidence in an application.

One honest uncertainty: the line between an immaterial intensification and a material change of use has never been reduced to a numerical test, and two inspectors on similar facts can land in different places. Plead ground (c) on the specifics of your property, not on a threshold you have read somewhere.

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 need the planning merits written up alongside the grounds, PlanScope can draft the Planning Statement for a ground (a) case in minutes. Enter your postcode on PlanScope to see which reports the site needs.

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