Established use and lawful use in planning explained

In planning terms a use is lawful if it has planning permission, or if the time limit for enforcement against it has run out, or if it never needed permission in the first place. That last route catches more cases than landlords expect. A flat carved out of a shop in 2009 with no application and no complaint has very likely gained immunity by now, and the way to put that beyond argument is a certificate of lawfulness of existing use or development under section 191 of the Town and Country Planning Act 1990.

Immunity is not the same as permission. A use that has become immune from enforcement sits in an odd position: the council cannot serve an enforcement notice, but there is no permission document, no approved drawings and no conditions. Lenders and buyers dislike that gap, which is why the certificate exists.

What makes a use lawful

Section 191(2) sets out three gateways. A use is lawful if no enforcement action may then be taken against it because the relevant time limit has expired, or because it did not involve a breach of planning control at all, and if it does not contravene any enforcement notice already in force.

That third limb catches people out. An extant enforcement notice does not expire with the passage of time, so a use carried on in defiance of one never becomes lawful however long it continues.

The second limb covers uses that were never development. Moving from a shop in Class E(a) to a cafe in Class E(b) is not a material change of use because both sit inside the same class. The same applies to a change permitted by the General Permitted Development Order, where the permission is granted by the Order rather than by the council.

Immunity through the passage of time

Section 171B of the 1990 Act sets the enforcement time limits. The old framework gave four years for building operations and for a change of use to a single dwellinghouse, and ten years for other material changes of use and for breaches of condition.

Section 115 of the Levelling-up and Regeneration Act 2023 replaced the four-year periods in England with a single ten-year period. The change applies to breaches occurring on or after the commencement date in April 2024, so older breaches keep the shorter period they accrued under. Check the commencement position on legislation.gov.uk before you rely on either figure, because the transitional wording does the real work here.

The clock runs from the date the breach began, not from the date the council found out. For a change of use that means the date the new use began in substance, which is rarely the date on an invoice or a tenancy agreement.

Deliberate concealment is the exception. Where a breach has been hidden, the council can apply to a magistrates' court for a planning enforcement order under section 171BA, and a successful order reopens the enforcement window even though the ordinary period has passed.

Why established use certificates no longer exist

Older title packs sometimes contain an established use certificate. These were issued under the Town and Country Planning Act 1971 and confirmed only that a use was established, which stopped short of confirming it was lawful.

The Planning and Compensation Act 1991 swept them away and substituted the present sections 191 and 192, creating the certificate of lawfulness of existing use or development and the certificate of lawfulness of proposed use or development. An old established use certificate is still evidence, and section 191 treats the use it describes as lawful, but nobody issues new ones.

Evidence that proves continuity

The burden of proof sits on the applicant, and the standard is the balance of probabilities. The Planning Practice Guidance on lawful development certificates is explicit that the applicant's own evidence can be enough on its own if it is sufficiently precise and unambiguous and nothing contradicts it.

Precision is what the case officer is testing. For a continuous residential or shared-house use, the material that usually does the job includes:

• council tax records and valuation band history for each unit
• tenancy agreements running consecutively, with gaps explained rather than ignored
• utility accounts and meter records in occupiers' names
• electoral roll entries for the address
• statutory declarations from occupiers, neighbours or the previous owner
• dated photographs, aerial imagery and internal layout plans

A single strand rarely convinces. Four strands that agree with each other usually do, and a statutory declaration from a tenant who lived there across the critical years carries more weight than a bundle of invoices.

Where an obligation under section 106 affects the land, that obligation runs with it regardless of how long a use has continued, so check the title as well as the planning history. Our note on deeds of variation under section 106A explains the only route to changing one.

Breaks in use and their effect

A gap does not automatically destroy immunity, but it invites two arguments. The first is abandonment: if the use has ceased, the premises have been left in a condition unsuited to it, time has passed and there is no evidence of an intention to resume, the courts have accepted that the right to resume can be lost.

The second is that an intervening use created a new planning unit, resetting the clock. A house let as a single family dwelling for three years between two periods of shared occupation is a real problem for a ten-year claim, because the ten years must be continuous and immediately preceding the application.

Intensification is the subtler risk. A use that changes in character rather than merely in volume can amount to a fresh material change of use with its own start date. Growth from a four-person shared house to an eight-person one, with the layout altered to match, is the sort of step an officer will probe.

Applying under section 191

The application goes to the local planning authority on the lawful development certificate form, with a site plan, a description of the use that is deliberately precise, and the evidence bundle indexed and paginated. Describe the use in the words you want to see on the certificate.

1. Settle the precise description first, including the number of units, the use class and any ancillary elements.
2. Fix the relevant date, which is the date of the application, and work backwards across the required period.
3. Assemble the evidence chronologically and write a short statement of case explaining what each document proves.
4. Obtain statutory declarations before submission rather than offering them later.
5. Pay the fee, which for an existing use application mirrors the fee for a planning application for the same development. Fees are indexed, so take the current figure from the published schedule.
6. If the authority refuses, or fails to decide within eight weeks, appeal under section 195 to the Planning Inspectorate.

There is no third-party right to object in the way there is on a planning application, because the question is one of fact and law rather than planning merit. Neighbours are often consulted anyway, and contradictory evidence from them is the commonest reason a claim fails.

What a certificate does and does not protect

A certificate under section 191 is conclusive as to the lawfulness of what it describes, as at the date of the application. Change the use afterwards and the certificate stops covering you.

It does not grant planning permission, so it cannot authorise works. It says nothing about building regulations compliance, nor about fire safety duties in a converted building, where separate obligations apply and our note on evacuation alert systems in blocks of flats sets out one of them. It does not override an Article 4 direction for any future change. And it does not switch off liability under the Community Infrastructure Levy for later development, although a lawful existing use can support an offset against chargeable floorspace, as the self-build exemption note shows for a different relief.

Nor does it cure a listed building breach. Listed building enforcement has no equivalent immunity period, so unauthorised works to a listed building stay open to enforcement action indefinitely.

If the next step is a formal application rather than a certificate, the supporting document set depends on the proposal and the site's constraints. The report types grouped by category shows what a council is likely to ask for.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.