Class MA lets you convert a Class E commercial building — a shop, office, café, gym, clinic or nursery — into Class C3 dwellings without a planning application. There is no floorspace cap and no vacancy requirement, so the constraint that decides most sites is the two-year use test.
This is the position as at September 2026, under Class MA of Part 3 of the General Permitted Development Order.
What changed in March 2024
Class MA was introduced on 21 April 2021 and effectively superseded Class O, the office-to-residential right, whose deadline for prior approval applications was 31 July 2021. Classes G and M are separate rights and are still in force.
On 5 March 2024, SI 2024/141 removed two limitations:
- The 1,500 sq m floorspace cap is gone. There is now no upper size limit on a Class MA conversion.
- The three-month vacancy requirement is gone. The building can be occupied and trading on the day you apply.
Together those changes brought large, tenanted buildings into scope — whole office blocks, not just upper floors of a parade.
The two-year use test
The building must have been in a qualifying use for a continuous period of at least two years before the date of the prior approval application. Since 1 September 2020 that means Class E. Before then it means the old Class A1 shops, A2 financial and professional services, A3 food and drink, B1 business, D1(a) medical or health services, D1(b) crèche, day nursery or day centre, or D2(e) indoor and outdoor sports other than an indoor swimming pool or skating rink.
This is the test that fails deals. A building that was a pub (A4) or a hot food takeaway (A5) before 2020 does not qualify through that period, because neither became Class E — both are sui generis. Our guide to use classes sets out which uses went where. Where the use history is undocumented, a lawful development certificate is the way to establish it before you exchange.
Where Class MA does not apply
- Sites of special scientific interest, listed buildings, scheduled monuments, safety hazard areas and military explosives storage areas;
- Areas of Outstanding Natural Beauty, National Parks, the Broads, World Heritage Sites and areas specified under section 41(3) of the Wildlife and Countryside Act 1981;
- Sites under an agricultural tenancy, without the express consent of both landlord and tenant.
Conservation areas are the notable exception — Class MA does apply in one. Where the scheme changes the use of all or part of the ground floor, the impact on the character or sustainability of the conservation area becomes a prior approval matter. Read our conservation areas guide before you assume that is a formality.
The bigger risk is an Article 4 direction. Many authorities have made directions withdrawing Class MA across town centres and employment areas since 2021. Check the council’s Article 4 register for the specific address, not the general area.
Class MA prior approval requirements
The council may only consider:
- Transport impacts, particularly safe site access;
- Contamination risks;
- Flooding risks;
- Noise from commercial premises affecting the intended occupiers;
- Impact on the character or sustainability of a conservation area, for ground floor changes;
- Adequate natural light in all habitable rooms;
- The impact on occupiers of introducing residential use into an area important for industry, waste management or storage and distribution;
- Loss of a registered nursery or an NHS health centre;
- Fire safety, where the building will contain two or more dwellings and meets the height condition in article 9A of the Development Management Procedure Order.
Where fire safety is in play the authority must consult the Building Safety Regulator, which took over that function from the Health and Safety Executive on 27 January 2026 under SI 2026/20. Build the extra consultation time into your programme.
Costs, deadlines and the things that are not permitted
- Fee: £260 for each dwellinghouse, with no cap, under the fee schedule effective 1 April 2026. A twenty-unit scheme is £5,200.
- Determination: 56 days. If the council has not notified you by then, you may proceed.
- Completion: within three years of the prior approval date.
- Unit size: article 3(9A) of the Order refuses permission to any new permitted development dwelling under 37 sq m gross internal area, or one that fails the nationally described space standard.
- External works: Class MA permits a change of use, not building operations. New windows, extensions or material alterations to the exterior need their own planning permission.
- No stacking: a building whose residential use came only from Class MA cannot then take extra storeys under Part 20 airspace rights. If you want both, the airspace scheme has to come first or go through a full application.
- Use is fixed afterwards: the building must remain in C3 use. Turning the units into an HMO later needs permission.
Identifying Class MA opportunities in BOOM!
The first question on any Class MA site is what the building is used for now and what it was used for two years ago. BOOM!’s Use Class layer, built on Ordnance Survey’s Land Use dataset, answers the first and narrows the second; the Article 4 Direction layer tells you whether the right has been withdrawn at that address.
Both sit in SiteSeeker alongside plot size, planning history, lease and title information, so you can filter a search to Class E buildings outside Article 4 areas rather than checking them one by one. SiteSeeker also surfaces landowner contact details, which feed straight into BOOM!’s DTV letter-sending workflow.
