What commercial to residential conversion actually means

Planning law controls the use of a building, not who occupies it. Turning a shop or an office into homes is a change of use, and in England it is governed by the use classes system.

Commercial premises usually sit in Class E, which covers a wide range of uses: shops, offices, restaurants and cafes, gyms, nurseries, medical and health services, professional services and light industrial space. Dwellinghouses sit in Class C3. Moving a building from E to C3 is a material change of use and needs consent.

There are two routes to that consent. Full planning permission, where the council assesses the scheme on its merits. Or Class MA permitted development, where the principle of the change is already granted nationally and the council only assesses a defined list of impacts through a prior approval application.

Class MA is faster, cheaper and far more predictable. It is also narrower, and it does not apply everywhere.

What is Class MA permitted development?

Class MA sits in Part 3 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015. It was introduced in August 2021, replacing the older Class O office to residential right and several others.

It permits the change of use of a building from Class E to Class C3 without a full planning application, provided the conditions are met and the council grants prior approval.

With full planning permission the council decides whether homes are acceptable there at all. Under Class MA that principle is already settled by national legislation, and the council can only refuse on the specific grounds the right allows. That is a far narrower set of objections.

It applies in England only. Scotland, Wales and Northern Ireland run separate systems and Class MA does not exist in any of them.

What changed on 5 March 2024

Most guidance still quotes the old rules, so here is what the amendment actually did.

The Town and Country Planning (General Permitted Development etc.) (England) (Amendment) Order 2024, SI 2024/141, came into force on 5 March 2024 and removed two of the biggest constraints on Class MA.

The 1,500 sqm floorspace cap was removed. Before that date, no more than 1,500 sqm of a building could be converted under Class MA, which pushed larger schemes into full planning or forced them to be split into phases. There is now no upper limit on the size of building that can be converted.

The three month vacancy requirement was removed. Previously the premises had to have been vacant for a continuous period of at least three months immediately before the prior approval application. That condition is gone, so a building in active commercial use now qualifies. Commercially this is the bigger of the two changes, because an owner can keep collecting rent while the application runs rather than engineering a void first.

Nothing else about Class MA changed. All other requirements, conditions and existing Article 4 directions continued to apply, and the amendment relates to England only.

If you are reading an article, a lender's guidance note or a council page that still quotes a 1,500 sqm limit or a vacancy period, it predates March 2024.

The conditions that still apply

Removing two restrictions did not make Class MA unconditional. These still stand.

• Two years of Class E use. The building must have been in a use falling within Class E for at least two continuous years before the application.
• Space standards. Every new dwelling has to meet the nationally described space standards, which sets a floor of 37 sqm for a one bed, one person flat and rises from there.
• Listed buildings are excluded. So are buildings within the curtilage of a listed building.
• Protected land is excluded. Sites of special scientific interest, National Parks, areas of outstanding natural beauty, the Broads and safety hazard or military explosives areas.
• Conservation areas are restricted. Ground floor uses in a conservation area are assessed on the impact of the loss of that use, so a ground floor shop in a conservation area is not a straightforward case.

Class MA also carries no affordable housing obligation, which is a large part of why it is commercially attractive compared with full planning on the same site.

What prior approval involves

Prior approval is a real application with a real refusal rate, not a notification.

You submit a description of the development, site and location plans, floor plans showing dimensions and room uses, and existing and proposed elevations. Taller buildings need a fire safety report, and flood risk assessments are required where the site calls for one.

The council then assesses a defined list of impacts rather than the scheme as a whole:

• Adequate natural light in all habitable rooms.
• Transport and highways impact, including safe site access.
• Contamination risk on the site.
• Flooding risk.
• Noise from nearby commercial premises affecting future residents.
• The impact of losing a ground floor use in a conservation area.
• Where relevant, the loss of a service such as a nursery or a health centre.

The council has 56 days to determine the application. If it does not decide within that period, consent is deemed to be granted.

Natural light is the most common reason for refusal. Deep floor plates with rooms that cannot reach a window are the recurring problem, particularly in office stock built for open plan use.

When you still need full planning permission

Class MA does not cover everything on a high street. You need a full application where:

• The building is not in Class E. Pubs, drinking establishments, hot food takeaways, cinemas, concert halls and live music venues sit outside Class E and are not eligible.
• The building is listed or in the curtilage of one.
• The site sits in a National Park, an AONB, an SSSI or another excluded area.
• An Article 4 direction has removed the right locally.
• The building has not been in Class E use for the full two years.
• You want to do something Class MA does not permit, such as extending the building or altering it beyond what the right allows.

Full planning is slower and the council can refuse on principle, but it also allows a scheme Class MA would never accommodate.

Article 4 directions

An Article 4 direction removes a permitted development right in a defined area. Councils have used them extensively against Class MA, particularly where they want to protect office space or a town centre's commercial character.

The effect is geographic and it can be tight. A direction may cover a single business district, a ward or a whole borough, and two buildings a few streets apart can sit on different sides of the line.

An Article 4 direction does not make conversion unlawful. It removes the automatic right, so the change needs a full planning application decided on its merits.

Check the register of directions for the local authority before you buy anything. The boundaries are published and this is the single cheapest piece of due diligence in the whole process.

What if you plan to let it short term?

A Class MA conversion gives you C3 dwellinghouses. That is residential use, and it is where a second set of rules begins rather than ends.

Letting a C3 dwelling on a short term basis can itself amount to a material change of use, depending on how intensively you do it. In Greater London there is a 90 night annual cap on entire home lets without planning permission. Elsewhere it is assessed as a question of fact and degree, and a separate Article 4 direction may apply to short letting even where the conversion itself was permitted.

The two regimes are independent. Prior approval under Class MA says nothing about whether you can then run the units as short lets, and a council that granted the conversion can still pursue enforcement over the letting.

Our guide to holiday let planning permission covers that second question in full. If you are weighing letting models for the finished units, our guide to serviced accommodation covers the economics.

Before you buy

Most Class MA problems are visible before exchange, and expensive afterwards.

• Confirm the building has been in Class E use for two continuous years, with evidence rather than an assumption.
• Check the Article 4 register for the local authority and find the boundary.
• Check the listing and conservation area status of the building and its neighbours.
• Work out whether every proposed habitable room can reach adequate natural light. This is the most common refusal and it is a design constraint, not a paperwork one.
• Check for noise from neighbouring commercial units, which is assessed from the future resident's point of view.
• Get a view on the services and structure. Commercial buildings have centralised plumbing and ventilation and residential conversion means running services to every unit.

This is general information, not planning or legal advice. Class MA cases turn on the specific building and the specific authority, so take advice on any scheme before you commit.