Sui generis: the uses that belong to no class at all

Sui generis is the use class explained by what it is not. Article 3(6) of the Town and Country Planning (Use Classes) Order 1987 takes a list of uses and declares that they fall within no class at all, and anything the Order never mentions is outside the classes by default. The consequence is simple and expensive: because there is no class, there is no free movement, so every change into or out of a sui generis use is a material change of use needing planning permission.

What sui generis means

The Use Classes Order groups uses so that a change within a class is not development. Move a shop to an office within Class E and no permission is required, because the Order says a change within the same class does not amount to development.

Sui generis uses sit outside that machinery entirely. Each one stands alone, which is exactly what the Latin says. There is no neighbouring use to slide into and nothing to slide out of.

That makes the category the most consequential part of the Order for anyone buying or letting commercial property, and it is why the first question on any acquisition should be which class the existing lawful use falls within, rather than what the previous occupier happened to do.

Uses listed as sui generis in the Order

The Order names a list. It includes theatres, amusement arcades and centres, funfairs, launderettes, petrol filling stations, premises selling or displaying motor vehicles for sale, taxi and vehicle hire businesses, scrapyards, waste disposal installations, retail warehouse clubs, hostels, nightclubs, casinos, betting offices, pay day loan shops and hot food takeaways.

The 2020 amendment moved a significant group into this category. Public houses, wine bars and other drinking establishments, drinking establishments with expanded food provision, hot food takeaways, cinemas, concert halls, bingo halls, dance halls and live music venues all sit outside Class E and outside the other classes.

That reorganisation is what catches people out. A high street unit that was an A4 pub before September 2020 did not join Class E with the shops and cafés. It became sui generis, and converting it to a café or a shop needs permission that a café converting to a shop would not.

Read the current consolidated text rather than a list in an old article, because the Order has been amended several times and the category has grown.

Uses that are sui generis because nothing covers them

The listed uses are only part of the picture. Any use the Order does not place in a class is outside the classes by default, and that residual group is larger than the list.

Builders' yards, car washes, crematoria, kennels and catteries, contractors' depots, storage of vehicles for hire, motorsport venues and large houses in multiple occupation beyond the size limit of Class C4 all tend to fall here. So do mixed uses where two distinct activities are carried on together without either being ancillary to the other.

The mixed use point is worth pausing on. A single planning unit carrying a workshop and a retail showroom of comparable importance may be a sui generis mixed use rather than either a workshop or a shop. Deciding that depends on identifying the planning unit first, and the reasoning is set out under how councils decide what they assess.

Why every change to or from one needs permission

The Order only removes the need for permission where a change falls within a class or is expressly permitted. Neither applies to sui generis uses, so the ordinary test in section 55 of the Town and Country Planning Act 1990 governs: is there a material change in the use of the building or land?

In practice the answer is almost always yes, because the uses in this category tend to have distinctive impacts. A hot food takeaway generates odour, late night activity and refuse. A car wash generates water discharge and queuing. A nightclub generates noise and dispersal patterns. Those differences are what put the use outside a class in the first place.

A few permitted development rights do allow specific movements involving sui generis uses, and they change periodically. Check Part 3 of Schedule 2 to the General Permitted Development Order 2015 in its current form rather than assuming either that a right exists or that it does not.

Intensifying an existing sui generis use can also amount to development in its own right, which is a separate question covered under doing more of the same.

Describing the use accurately

The description of development on the application defines what is permitted, and with sui generis uses there is no class to fall back on if the wording is loose.

Name the existing lawful use, name the proposed use, and state that the proposed use is sui generis. Officers value it, and it protects you later: a permission described as "change of use to commercial" invites an argument about what was actually authorised.

Where a change involves cooking, the extraction and odour case has to be made at the same time. A Ventilation and Extraction Statement setting out the flue route, termination height, filtration and maintenance regime is normally expected with any hot food application, and the environmental health officer will read it before the case officer does.

Conditions and enforcement on sui generis premises

Because there is no class to contain the use, councils rely heavily on conditions. Expect restrictions on opening hours, on the hours of deliveries and refuse collection, on the number of covers or customers, on external seating, on plant noise limits and on the specific use permitted.

That last one matters. And a condition tying the permission to a named use prevents any later change without a further application, which is the authority's way of keeping control it would otherwise lack. Read it before you assume the premises can trade differently.

Enforcement follows the ordinary route. A material change of use carried out without permission can be the subject of an enforcement notice, and the time limits for immunity in England were altered by the Levelling-up and Regeneration Act 2023, so check the position for the date the change occurred.

Confirming the position with a certificate

Where the lawful use is uncertain, and on older premises it very often is, the way to settle it is a certificate of lawfulness. Section 191 confirms an existing use as lawful, and section 192 confirms that a proposed use would be lawful.

Both are decided on facts and law rather than on policy, which makes them the right tool for a classification question. A certificate confirming that premises are lawfully a drinking establishment, or that a proposed change would not be a material change of use, is worth more to a lender and a buyer than any amount of correspondence with the council.

The same approach helps where a classification is borderline, as it often is with drive-through units and with hybrid retail and service operations.

PlanScope drafts the Planning Statement and supporting documents for a change of use application from your answers and the constraint data it checks at the postcode, then flags what still needs professional input.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.