Sui Generis Use Class: Meaning and Examples

Sui generis meaning in planning

The Planning Portal puts it simply. "Sui generis" is a Latin term that, in planning, "means 'in a class of its own'".

Most buildings in England sit in a use class. The Use Classes Order 1987, as amended from 1 September 2020, groups similar uses together. Class E covers shops, offices, cafes and gyms. C3 covers homes, and C4 covers small HMOs.

A use becomes sui generis in one of two ways:

1. Named in the Order. Article 3(6) lists uses that no class includes, such as theatres, casinos and pubs.
2. Outside a class's limits. The use is close to a class but breaks its limit, such as an HMO with more than six residents.

Why it matters is in the Town and Country Planning Act 1990. Section 55(2)(f) says a change to another purpose "of the same class" is not development. A sui generis use has no class, so that exemption never helps it.

Several common town-centre uses left the old classes in 2020. For every class in force, see use classes explained. Our guide to Class E use class explained shows which ones stayed in.

List of sui generis uses in the Use Classes Order

Article 3(6) of the Use Classes Order opens with one line: "No class specified in Schedule 1 or 2 includes use". It then lists the uses below, by letter. We read the list on legislation.gov.uk on 4 November 2026.

The letters follow the printed Order. There is no (w), and in Wales letter (k) is a betting office. The previous classes come from the Planning Portal's use classes page.

The list is not the whole story. Any use outside the limits of every class is sui generis too. The council decides that on the facts of each building.

If you are buying, confirm the lawful use before you exchange. The certificates and evidence that prove it are set out further down.

Large HMOs: sui generis above six residents

An HMO with up to six residents sits in Class C4. Above six residents, it falls outside that limit and becomes a sui generis HMO.

This matters for the route. Class L permitted development only switches a house between C3 and C4. It never reaches a large HMO, so a seven-bed HMO needs a planning application.

Planning is only one of the consents. A mandatory HMO licence applies from five people in two or more households, whatever the use class.

We do not repeat the detail here. Our guide to HMO planning permission covers the London policy tests. What is an HMO explains the legal definition. For the build itself, see our HMO conversion service.

Changing to or from sui generis

Section 55(1) of the 1990 Act makes "any material change in the use" of a building development. Section 57(1) says development needs planning permission.

So the rule is plain. If a change to or from sui generis is material, you need permission. The only way round it is a permitted development right in Part 3 of the General Permitted Development Order 2015 (GPDO).

Class N prior approval covers transport, contamination, flooding and natural light. Design is added when building works are part of it. Listed buildings are excluded.

Outside these rights, a change of use usually needs a full application. That includes a pub, nightclub, theatre or large HMO becoming homes. Our guide to pub to residential conversion walks through one of the hardest cases.

Moving into sui generis usually needs permission too. A Class E shop that becomes a hot food takeaway leaves its class. So does a family house that becomes a seven-person HMO.

Evidence and fees for a sui generis change of use

Planning policy protects some sui generis uses, such as pubs. For those, the council looks for evidence before it accepts the loss of the old use.

For pubs, national policy sets a floor. NPPF policy HC6 asks for marketing for the existing use for at least 12 months, where commercial viability is an issue. The London Plan asks for at least 24 months of marketing as a pub.

At Allitsen Road in St John's Wood, the building was a derelict former members' club. A sui generis club has no automatic route to residential. The council expects sustained evidence the old use is dead.

Our plan builds that proof from the club's own trading and vacancy records, plus a properly run marketing campaign. Our Allitsen Road feasibility study planned 12 to 18 months of it into the deal.

You may also need to prove the lawful use itself. A section 191 certificate confirms an existing use is lawful. In England, enforcement action is generally time-barred ten years after the breach. A section 192 certificate confirms a proposed use would be lawful.

A rise to £732 for other changes of use is proposed from 8 December 2026. The draft regulations had not been made on 4 November 2026. Councils aim to decide a non-major application in 8 weeks, unless you agree longer in writing.

Own or buying a pub, club or hostel? Send us the address and get a free route check. You get the route, the evidence period and the build cost before you exchange or apply.