Class MA prior approval: the use history and natural light tests

Class MA of Part 3 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015 allows premises in Class E, the commercial, business and service class, to change to residential use in Class C3 through prior approval rather than a full application. Two conditions decide most class ma prior approval cases before design ever comes into it: whether the building has the qualifying use history the class demands, and whether every habitable room will have adequate natural light.

The class has been amended since it was introduced in 2021, including changes to the floorspace limits. Check the current text of the Order rather than an older summary, including this one.

What Class MA of Part 3 permits and which uses qualify

The class permits a change of use from Class E to Class C3 dwellinghouses, together with the building operations reasonably necessary to achieve it. Class E is broad. It covers shops, financial and professional services, cafes and restaurants, offices, research and development, light industrial, clinics and health centres, creches and day nurseries, and indoor sport and fitness.

That breadth is the opportunity and the trap. A use has to fall within Class E, and several familiar high street uses do not. Drinking establishments, hot food takeaways, cinemas, live music venues and betting shops are sui generis, and premises in those uses cannot use Class MA at all.

Nor can Class MA be used where the building is listed or in the curtilage of a listed building, or where it is a scheduled monument, in a safety hazard area, in a military explosives storage area, or on a site of special scientific interest. Other designated land carries its own restrictions. Check every exclusion in the current text against the site, because eligibility is jurisdictional and no amount of design work cures it.

The qualifying use history the council will check

The class requires the building to have been in a use falling within Class E for a continuous qualifying period immediately before the date of the application, and to have been vacant for a shorter continuous period immediately before it. The periods are stated in the Order and have been the subject of amendment, so read them there.

Councils check this properly, and it is the most common reason for refusal. Evidence that works looks like this.

• Business rates records from the Valuation Office, showing the rateable use and the dates.
• Leases, licences and tenancy agreements covering the whole qualifying period without gaps.
• Filed accounts or trading records for the occupying business.
• Utility accounts and bills in the occupier's name.
• Dated photographs, signage, and archived listings showing the premises trading.
• Statutory declarations from the landlord, the agent or the former occupier.

Continuity is the point. A gap of a few months in the middle of the qualifying period is exactly what an officer will ask about, and an application that presents four documents from convenient dates without addressing the gaps is asking to be refused.

And the vacancy requirement is the mirror image. You have to show the premises were vacant immediately before the application, which means evidence of when the last occupier left, not merely an assertion that the shop looks empty.

Where a building has had several uses, note that a change within Class E does not restart the clock, because the requirement is Class E use rather than a particular sub-use. A former office that became a clinic remains in Class E throughout.

Natural light to all habitable rooms

The prior approval matters include the provision of adequate natural light in all habitable rooms of the proposed dwellings. It is the test that catches deep office floorplates and back-of-shop conversions, and it is not negotiable by design ingenuity alone.

Habitable rooms means bedrooms, living rooms and kitchen-dining spaces used for living. Bathrooms, hallways, utility rooms and internal circulation are not habitable rooms, so they may be internal.

A room with no window at all fails. The Order does not fix a numerical standard for what is adequate beyond that, so councils apply judgement informed by recognised daylight guidance, and practice varies. What consistently helps is evidence rather than assertion.

Present a room-by-room schedule with the window area, the room area, the room depth from the window wall, the orientation, and anything external that obstructs the light such as a lightwell, an overhang or a facing building. Where rooms are marginal, a modelled daylight assessment gives the officer something to agree with. A Daylight and Sunlight Assessment prepared to recognised guidance is worth its cost on any deep-plan building, and it is far less costly than a refusal and a resubmission.

Design responses that work include lightwells cut through the plan, reducing unit depth and accepting fewer units, dual aspect layouts at corners, and putting circulation and services in the dark core rather than bedrooms.

Flooding, contamination, noise and transport considerations

The other prior approval matters are narrower than a full application but wider than people expect.

Transport impacts, particularly highway safety, cover servicing, refuse collection, cycle parking and the removal of any existing loading arrangement. Contamination risks matter on former light industrial premises, and where a risk is identified the council will expect the standard sequence of desk study and, where indicated, investigation. Land contamination reports must be prepared by suitably qualified and experienced people, so a Land Contamination Assessment draft is a starting point for that professional rather than a substitute.

Flooding is assessed on the same basis as any residential proposal, which means a site-specific assessment where the premises sit in Flood Zone 2 or 3, and residential use above ground floor may be the answer on a constrained site.

Noise deserves particular attention. The matter is the impact of noise from existing commercial premises on the future residents, which is the reverse of the usual test. A flat above a bakery with a 4am start, or beside a gym with overnight plant, has to be shown to be liveable. A Noise Impact Assessment covering the existing commercial sources, the internal criteria and the mitigation is the right answer, and it protects the neighbouring business as much as the applicant.

There is also a matter about the effect of losing ground floor Class E use in a conservation area, where that use is important to the character of the area, and one about introducing residential use into an area important for general or heavy industry, storage and distribution or waste management.

Space standards and the condition attached

Class MA carries a condition requiring the dwellings to meet the nationally described space standard. That is a genuine floor area requirement, not guidance, and it applies to gross internal area per dwelling by bedspaces, to individual bedroom sizes and to floor-to-ceiling height.

Run the areas before you draw anything. A commercial floorplate divided into as many units as the plan will take usually produces studios below the minimum, and the fix is fewer, larger units. Storage provision within the unit counts and is often forgotten.

Where the building is 18 metres or more in height or has seven or more storeys, fire safety brings a separate set of requirements, and those apply regardless of the route into residential use.

Assembling the notification pack

A prior approval application is determined within 56 days, so the pack has to be complete on day one. There is no useful equivalent of a long negotiation.

1. The application form and fee, calculated per dwelling on the current schedule.
2. Existing and proposed floor plans and elevations, with room areas and window dimensions annotated.
3. The use history evidence bundle with a chronology cross-referencing each document.
4. Vacancy evidence with dates.
5. A natural light schedule, with a daylight assessment where any room is marginal.
6. Assessments for the other prior approval matters that apply to the site.
7. A short covering Planning Statement taking each prior approval matter in turn and pointing to the evidence.

That last document does more work than its length suggests. Officers assessing prior approval are working through a checklist, and a submission organised to match the checklist gets decided rather than queried.

Illustrative example: a two-storey former estate agency, in Class E use since 2018 and empty since the spring, with a 14 metre deep ground floor. The use history is straightforward from rates records and the lease. The problem is the rear of the ground floor, where a bedroom would sit 11 metres from the only window. Cutting a lightwell or converting the rear to storage and circulation, with one unit instead of two, is what makes the scheme approvable.

This is general guidance, not legal advice. Class MA has been amended more than once, so check the current text of the Order and confirm the position with your local planning authority or a qualified professional before relying on it.

Work out which prior approval matters your building engages before you draw the units. Enter your postcode on PlanScope to see what a commercial to residential conversion is likely to need.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.