Class MA prior approval: the vacancy and floorspace tests

The Class MA prior approval requirements have moved twice since the right was introduced on 1 August 2021, and the tests most investors still quote from memory are the two that changed. The condition that decides applications now is the use history: the building must have been in a use falling within Class E of the Use Classes Order for a continuous period of at least two years before the date of the application. Get that wrong and the prior approval is invalid whatever the merits of the conversion.

Class MA permits a change of use from Class E, the commercial, business and service class, to Class C3 dwellinghouses. It sits in Part 3 of Schedule 2 to the General Permitted Development Order 2015, and it is a prior approval right rather than a free-for-all. The council still gets to say no, but only on the grounds the order gives it.

The two-year Class E use condition

Two continuous years, in Class E use, immediately before the application date. Three parts of that sentence cause trouble.

Continuity is the first. A building that sat empty for part of the period has not necessarily broken continuity, because the lawful use can persist through a vacancy where there is no intervening use and no abandonment. Councils vary in how readily they accept that, and the argument gets harder the longer the gap runs.

The Class E point is the second. Class E was created in September 2020 and swept up the former A1, A2, A3, B1, D1 and D2 uses in part. A building lawfully used as a shop before 2020 is treated as being in Class E now. A building in a sui generis use, a hot food takeaway or a drinking establishment for example, is not in Class E at all and cannot use Class MA.

The third is the date the clock stops. It runs to the date of the prior approval application, not to the date the building was bought or the date works are proposed to start.

What the vacancy and floorspace conditions now say

Class MA as made in 2021 carried two further hurdles. The building had to have been vacant for a continuous period of at least three months immediately before the application, and the floorspace changing use could not exceed 1,500 square metres.

Both were amended out of the order in 2024, following the government consultation on changes to permitted development rights. The practical effect is that a fully occupied building can be the subject of an application, and that the route is open to larger buildings than before.

Two cautions before you act on that. The order is amended often, sometimes several times in a year, so read the current consolidated text of Class MA on legislation.gov.uk rather than a summary. And a council officer working from an older internal checklist may still ask for vacancy evidence, which is easier to answer with a short covering note citing the amending instrument than with an argument at week seven.

The prior approval matters and what they mean in practice

The council can only consider the matters the order lists. In broad terms those are transport and highways impacts, contamination risk, flooding risk, the impact of noise from commercial premises on the future residents, the provision of adequate natural light in all habitable rooms, and, in a conservation area, the impact of the loss of a ground floor use. Where the building is in an area important for heavy industry or storage and distribution, the effect on those uses can also be considered.

Natural light is the one that catches conversions of deep-plan buildings. There is no numerical standard written into the order, so the assessment is a matter of judgement on plans that show window positions, room depths and any lightwells. Rooms with no window at all will fail.

Noise deserves the same attention where the building sits above or beside a restaurant, a gym or a plant room. A short acoustic note with measured background levels answers the point before it is raised, and a full noise impact assessment is proportionate where a licensed premises is next door.

Contamination comes up on former light industrial units within Class E. A desk study is usually enough at prior approval stage, with intrusive work secured by condition.

Transport is usually the easiest matter to answer and the one most often ignored. A town centre building losing a shop and gaining three flats generates fewer trips than the use it replaces, and saying so in two sentences with a parking position and a bin and cycle store location closes the point. Where the building has no off-street parking and sits in a controlled parking zone, say that too, and confirm whether future occupiers would be eligible for permits.

Flood risk is answered by the Environment Agency flood map for planning plus the surface water map. In Flood Zone 2 or 3 the council will expect a flood risk assessment addressing safe access, escape and finished floor levels, and residential use is a more vulnerable classification than the Class E use it replaces. That change in vulnerability is the point an officer will test.

Assembling the evidence pack

Councils determine Class MA applications in eight weeks and the determination period is not generous once consultation is under way. The pack that avoids a refusal on evidential grounds contains:

• business rates records for the full two-year period, obtained from the billing authority
• leases, licences or tenancy agreements covering the same period
• VAT registration or filed accounts showing trading at the address
• dated photographs of signage, fit-out and occupation
• a statement from the previous owner or occupier where ownership changed
• floor plans marked with existing and proposed use, and a floorspace schedule

Assemble it before you apply. Reconstructing a use history after a refusal is slower and more expensive than doing it once, and the eight-week clock does not pause while you look for paperwork.

A short planning statement tying that evidence to each condition and each prior approval matter is not required by the order, and case officers read it anyway.

Where Class MA does not reach

The right is excluded on listed buildings and land within their curtilage, scheduled monuments, sites of special scientific interest, safety hazard areas and military explosives storage areas. Article 4 directions remove it in parts of some boroughs, particularly in central London office areas, and those directions have to be checked on the council's own mapping rather than assumed.

Class MA also does not permit the building works. External alterations, new windows, balconies and roof extensions need their own permission or a separate permitted development right, and a scheme that only works with a new stair core is a full planning application in disguise.

Illustrative example: a two-storey former estate agency and print shop, in Class E use since 2018, with rates records showing continuous occupation. The ground floor converts to two flats and the first floor to one. Rear rooms are reconfigured so that every habitable room has a window. Prior approval is sought with a rates history, an acoustic note addressing the takeaway next door, and a contamination desk study. The figures and sequence here are illustrative.

If the use history is arguable, a certificate of lawfulness for a proposed use under section 192 of the Town and Country Planning Act 1990 is the only formal way to confirm that the conversion would be lawful. It costs more time at the front end and it removes the risk of building out an unlawful scheme.

PlanScope can draft the planning statement and the supporting technical documents that sit behind a Class MA submission, and the full report index shows which of the 66 types map onto the prior approval matters. Enter your postcode on the PlanScope home page to see which reports the site is likely to need before you commission anything.

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.