Class MA or Class M: two routes to residential

Class M and Class MA both convert commercial floorspace to housing without a full planning application, and they are not interchangeable. Class M covers small units up to 150 m² and permits the building works needed to carry out the conversion. Class MA covers commercial, business and service premises with no equivalent works limb, so any external alteration needs its own permission. Both sit in Schedule 2 Part 3 of the Town and Country Planning (General Permitted Development) (England) Order 2015, and both run through prior approval.

Pick the wrong one and the application is refused for failing a limit rather than on its merits. Worse, you may find you have a change of use permitted and no consent for the shopfront you intended to replace.

What each class permits

Class M allows a change of use to a dwellinghouse from a set of specified retail and service uses, including shops, financial and professional services, betting offices, pay day loan shops, launderettes and hot food takeaways. It also allows building operations reasonably necessary to convert the building. That second limb is the real prize: new windows, an altered entrance, internal structural work and the external changes conversion demands can come within the right.

Class MA allows a change of use from the commercial, business and service class, Class E of the Use Classes Order, to a dwellinghouse. Class E is wide, covering shops, cafes and restaurants, offices, research and development, light industrial, clinics, creches, gyms and indoor sport. The class permits the change of use and nothing more.

Read the current text of each class before you rely on a summary. Part 3 has been amended repeatedly since 2015 and the specified uses, the limits and the prior approval matters have all moved.

Vacancy, use history and floorspace compared

The vacancy and floorspace rows are the ones to verify at the point of application. Class MA was introduced in 2021 with a three month vacancy condition and a 1,500 m² cap, and both were removed by amendment in 2024. Conditions in Part 3 change with each amending order, so check the text on legislation.gov.uk on the day you apply rather than working from an older note.

The two year continuous use requirement for Class MA has stayed, and it is the condition that defeats most applications. A unit that was vacant for eighteen months, or that moved from Class E to a sui generis use at some point, may not qualify however suitable it looks.

Which prior approval matters each engages

Both classes limit the council to the matters the class specifies. The lists overlap but are not the same, and reading the wrong list produces a submission with a missing document.

Matters that commonly appear in both: transport and highways impacts, contamination risks on the site, flooding risks, and the provision of adequate natural light in all habitable rooms of the new dwellings.

Class MA adds further matters, among them the impact of noise from commercial premises on the intended occupiers, the impact on the sustainability of a conservation area where the change relates to the ground floor, and, in some circumstances, fire safety and the loss of services the local area relies on. Where the building is 18 metres or more in height, fire safety material is likely to be needed in any event.

Natural light is the matter that catches deep-plan units. A ground floor shop with a single frontage and a long back room cannot give every habitable room adequate natural light without alteration, and under Class MA you cannot alter the fabric under the same right. Class M can, which is often the deciding factor on a small unit.

Article 4 directions affecting each

Many local planning authorities have made Article 4 directions removing Class MA across town centres, primary shopping areas and designated retail frontages. Those directions are site specific and the pattern varies between neighbouring boroughs. Class M directions exist too, though they are less widespread.

Check the authority's Article 4 register before anything else, because a direction removes the right entirely and no amount of good evidence rescues the application. The national register of planning data publishes Article 4 direction boundaries for many authorities, and the council's own map is the definitive version.

A direction made after you submit does not bite on a valid application already lodged, but one made before you submit does.

Space standards and natural light

Since 2021 new dwellinghouses created under Part 3 and Part 20 of the Order have to meet the Nationally Described Space Standard. That is a condition of the right rather than a prior approval matter, so a unit that does not meet the standard is outside the right whatever the council says about the other matters.

The standard sets minimum gross internal areas by number of bedrooms and bedspaces, minimum bedroom sizes and a floor-to-ceiling height. On a retail unit with a 2.4 metre ceiling and limited depth, the arithmetic decides how many units are possible before any design work starts. Run it first. The comparison of the space standard against local minimum sizes sets out where authorities ask for more.

Evidence packs for each application

For Class M, expect to need existing and proposed plans and elevations covering the building operations, floor areas demonstrating the 150 m² limit, a location plan, and material on the specified matters: a transport note, a contamination screening assessment, flood risk information where relevant and a natural light statement with room-by-room daylight provision.

For Class MA, add evidence of the qualifying use for two continuous years. Business rates records, a lease or licence, accounts, utility bills and dated photographs all help, and a statutory declaration is sometimes used where the documentary trail is thin. Where the unit sits under or beside a bar, a takeaway or a workshop, a noise assessment addressing the effect of that use on future residents is usually the single most important document.

Both benefit from a short covering statement that walks the validation officer through each specified matter in the order the class lists them. It costs an hour and removes most invalidation queries.

Choosing the right class for a mixed unit

Where a building has a Class E ground floor and existing flats above, the Class E part is what Class MA can convert and the residential part is irrelevant to the qualifying use. Where a ground floor unit is under 150 m² and needs external alteration, Class M is usually the better route because the works come with it. Where the unit is larger, or the existing use is an office or a gym that never fell within the Class M list, Class MA is the only permitted development option.

And where neither fits, a full planning application is not a defeat. It lets you argue design, put an amenity case and ask for conditions you can live with, which a prior approval cannot. A Planning Statement that addresses the loss of the commercial use directly tends to do better than a prior approval application that fails on a technicality.

PlanScope can draft the supporting documents for either route, including transport, contamination, flood risk and noise material, from a postcode and a set of answers, with gaps flagged rather than filled. Browse the full set on the report index. Reports should be reviewed before submission and PlanScope does not guarantee planning approval. This is general guidance, not legal advice, and a lawful development certificate is the only formal way to confirm that works are lawful.