Class MA: commercial to residential prior approval

Class MA lets a building in commercial, business and service use become dwellings without a full planning application, and the class ma prior approval requirements are stricter than the headline suggests. The building has to have been in Class E use for at least two years, the site must not carry one of the excluded designations, the new flats must meet national space standards and every habitable room needs adequate natural light. Get any of those wrong and the council refuses prior approval rather than negotiating.

The qualifying conditions

Class MA sits in Part 3 of Schedule 2 to the General Permitted Development Order 2015. It permits a change of use from Class E, the broad commercial, business and service class created in 2020, to Class C3 dwellinghouses.

Two conditions define whether the right exists at all. The building must have been in Class E use, or a use that would now fall within Class E, for a continuous period of at least two years before the date of the application. And the change must be a change of use only, because Class MA does not permit building operations. Anything structural, any extension, any new external staircase and most alterations to the elevations need their own permission.

That last point derails more schemes than the designations do. An office plan that cannot become flats without new windows, a new entrance or a rooflight needs a parallel application, and a council is entitled to determine that application on its own merits while the prior approval proceeds.

Vacancy and the two year use requirement

When Class MA was introduced the building also had to have been vacant for a continuous period of three months immediately before the application, and the floorspace changing use was capped at 1,500 square metres. The Order was amended in March 2024 and both of those restrictions were removed.

The two year prior use condition remains. Evidence it properly: business rates records, lease documents, utility accounts, dated photographs and, where the use has changed within the period, whatever shows that the earlier use also sat within Class E. Councils do check, and a prior approval granted on a false premise is vulnerable.

This class has been amended more than once since 2021, so read the current consolidated version of Class MA rather than a commentary written when it was introduced. That is also true of the limits and conditions attached to Class MA, which have moved with the amendments.

The matters the council can consider

Prior approval is a closed list. The council cannot refuse because it dislikes the principle, and it cannot apply the whole development plan. What it can consider under Class MA is:

• Transport impacts, particularly safe site access.
• Contamination risks on the site.
• Flooding risks on the site.
• Impacts of noise from commercial premises on the intended occupiers.
• Where the site is in a conservation area, the impact of the loss of a ground floor use.
• Where the site is in an area the authority considers important for general industry, storage and distribution, waste management or a mix of those, the impact of introducing residential use on the intended occupiers.
• Adequate natural light in all habitable rooms.
• Fire safety, for buildings that meet the relevant height criteria.

The noise matter runs in an unfamiliar direction. It protects the future residents from the existing commercial neighbours rather than protecting neighbours from the development, so an assessment of the plant on the adjoining unit and the servicing yard behind it is doing the work. Where a food business sits below the conversion, the extract arrangements become the issue, and a ventilation and extraction statement for the neighbouring use is often what settles it.

Transport impacts are usually answered by a short transport statement covering access, servicing, refuse collection and cycle parking, rather than by a full assessment.

Natural light and window provision

Every habitable room has to have adequate natural light, and a habitable room with no window at all is fatal. This is the condition that kills deep plan office conversions, because the middle of a large floorplate simply cannot be lit.

Provide a daylight assessment rather than an assertion. Room by room, give the window area, the room depth, the orientation and the obstruction, and where a light well or an internal court is relied on, model it. An officer looking at a plan with a bedroom five metres from the nearest window will refuse, and no amount of narrative fixes that.

The practical response is to design fewer, better units. A floorplate that yields six workable flats with real windows is worth more than a refusal on twelve.

Space standards and the internal layout

Dwellings created under permitted development have to meet the nationally described space standard. That sets a minimum of 37 square metres for a one bedroom, one person flat with a shower room, with higher figures where a bath is provided and for larger occupancies, along with minimum bedroom areas, floor to ceiling heights and built-in storage.

Show compliance on the drawings with a schedule of areas, and be honest about the numbers. Gross internal area measured to the inside face of the external wall is the basis, and a schedule that quietly includes the thickness of partitions will be checked.

Storage and circulation are where small conversions fail the standard even when the headline area passes. So are ceiling heights in buildings with deep service zones, because dropping a ceiling to run drainage across a plan can take a room below the minimum.

Where the right does not apply

Class MA is excluded on a list of designations and situations. Listed buildings and land within their curtilage. Scheduled monuments and their curtilage. Sites of special scientific interest. Safety hazard areas and military explosives storage areas. Protected landscapes, meaning National Parks, National Landscapes, the Broads and World Heritage Sites.

Conservation areas are not on the exclusion list. They bring the extra prior approval matter about the loss of a ground floor use, which in a shopping frontage is a real test rather than a formality.

Check the designations before spending anything. The national planning data service and the council's own mapping will show most of them, and the listed building question needs the national list rather than a local assumption, because curtilage listing catches outbuildings that are not themselves on the list.

Article 4 directions and how to check

Local authorities have made many Article 4 directions removing Class MA, particularly in central business districts, designated employment areas and town centres. A direction removes the right entirely, and the answer is then a full planning application judged against the development plan.

Check three places: the council's own Article 4 register or policies map, the national planning data service, and the officer at the duty desk. Directions come into force on a stated date and can be made with immediate effect in limited circumstances, so a check made six months ago is not a check. The pattern in the capital is set out in the piece on Article 4 directions in London and office to residential.

Assembling the prior approval submission

The application itself is short, and the evidence around it is not.

1. The application form for prior approval under Class MA, with the fee from the current national schedule.
2. A location plan and a block plan.
3. Existing and proposed floor plans, with a schedule of gross internal areas against the space standard.
4. Elevations, where any change is proposed, with a note of what is being applied for separately.
5. Evidence of two years of Class E use, presented as dated documents rather than a statement.
6. A daylight note covering every habitable room.
7. A noise assessment addressing commercial sources affecting the intended occupiers.
8. Contamination and flood risk information proportionate to the site history and flood zone.
9. Fire safety information where the building height engages it, which is a substantial piece of work in its own right and is covered in the note on fire safety in Class MA conversions.

The determination period is 56 days from a valid application, and if the authority does not determine it within that period the development may proceed in accordance with the application. That deadline cuts both ways: an incomplete submission invites a refusal rather than a request for more information, because the officer has no time to ask. For a sense of how the whole sequence runs on a real floorplate, the walkthrough of an office to flats conversion follows it end to end.

PlanScope drafts the supporting statements for a Class MA submission from your building details and the constraints it detects, flagging the site facts a surveyor or acoustician has to confirm. Enter your postcode on PlanScope to see what the conversion is likely to need.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. A lawful development certificate is the only formal way to confirm that works are lawful. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.