Class MA or Class Q prior approval

Class MA converts commercial, business and service premises in Use Class E into homes. Class Q converts agricultural buildings into homes. They sit in the same part of the General Permitted Development Order, they both work through a prior approval application rather than full planning permission, and almost nothing else about them is the same. The qualifying periods differ, the prior approval matters differ, and the designated land restrictions differ enough that a building can qualify under one and be excluded outright from the other.

What each class permits

Class MA sits in Schedule 2, Part 3 of the Town and Country Planning (General Permitted Development) (England) Order 2015. It permits a change of use from Class E, which covers shops, offices, restaurants, gyms, nurseries, clinics and light industrial premises, to Class C3 dwellinghouses.

Class Q, in the same Part, permits a change of use from a building used for agriculture, together with the building operations reasonably necessary to convert it. That second half is what makes Class Q distinctive. Class MA is a use change, and any external alteration needs its own permission. Class Q carries limited building works with it.

Qualifying periods of previous use

This is the first filter, and it is where most enquiries stop.

For Class MA the building must have been in Class E use for a continuous period of at least two years before the date of the application, and it must have been vacant for a continuous period of at least three months immediately before that date. Both tests are evidential. Rates records, leases, utility bills and dated photographs carry more weight than a statement of fact.

For Class Q the building must have been used solely for agriculture as part of an established agricultural unit on 20 March 2013, or, where it came into agricultural use later, for ten years before the date of the application. Equestrian use is not agriculture. A building put up for storage of non-farm machinery is not agriculture either, whatever it looks like.

Keep the evidence pack together from the start. A land agent's records, dated aerial imagery, subsidy claim paperwork and machinery invoices all help. Authorities refuse Class Q applications on evidence alone more often than on the merits of the conversion, and there is no way to cure that at appeal without the documents.

Size and unit limits

The limits have moved. Class MA was introduced with a floorspace cap that a 2024 amendment removed, and Class Q was widened in 2024 to allow more and larger units than the original version.

Because the numbers have changed twice in recent years, read the current consolidated text of the Order on legislation.gov.uk rather than any secondary summary, including this one. Appeal decisions from 2022 were decided on limits that no longer apply.

Matters for prior approval under each

Prior approval is not a formality. The authority can refuse on any of the listed matters, and a refusal on one of them ends the route.

Class MA engages transport and highways impacts, contamination risk, flood risk, the effect of noise from nearby commercial premises on the future residents, the provision of adequate natural light in all habitable rooms, and, in a conservation area, the impact of losing a ground floor use. Fire safety is engaged where the building is tall enough to bring the Building Safety Act 2022 framework into play, which is where a Fire Statement prepared by someone with fire engineering competence becomes necessary rather than optional.

Class Q engages transport and highways impacts, noise, contamination, flood risk, natural light in habitable rooms, design and external appearance, and whether the location or siting makes residential use impractical or undesirable. That last matter has no equivalent under Class MA and is the one that refuses most barn conversions. A building at the end of a 400 metre unmade track with no passing places invites it.

Natural light is worth singling out. It applies to both classes now, it applies to all habitable rooms, and a deep-plan office floor or a windowless barn will fail it unless the design creates openings. Since Class MA carries no building works, creating those openings needs a separate planning application, which changes the programme completely.

Designated land and Article 4

Neither class applies to a listed building or a scheduled monument.

Class Q is excluded from the designated land defined in the Order, which takes in National Parks, the Broads, National Landscapes, conservation areas and World Heritage Sites, along with sites of special scientific interest and various safety and military areas. For a farm inside a National Landscape, Class Q is simply unavailable and a full application is the only route, which our guide to converting a barn by full application deals with.

Class MA operates in conservation areas, with the extra prior approval matter about ground floor use, but is restricted elsewhere. Check the Order rather than assuming.

Then check for an Article 4 direction. Many authorities have removed Class MA across town centres and primary shopping frontages to protect retail and employment floorspace, and some have removed it borough-wide. An Article 4 direction does not stop the scheme. It means a full planning application, judged against the development plan, with the local policy on loss of employment land applying in full.

Choosing the right route for a building

Work through it in this order, and stop at the first failure.

1. Is the building listed, scheduled, or on land where the class does not apply.
2. Does the previous use meet the qualifying period, with documentary evidence.
3. Is there an Article 4 direction covering the site.
4. Do the unit sizes and totals work under the current limits.
5. Can every habitable room get adequate natural light without works that fall outside the class.
6. Is the access, noise environment and flood position defensible on the prior approval matters.

A building that fails at step five under Class MA often works as a full application instead, where fenestration changes and internal reconfiguration can be considered together. That is not a defeat. It is a different consent with a different evidence base, usually including a Planning Statement and a design rationale.

For an agricultural building, sequencing matters in a way it does not for an office. Bat and barn owl surveys have seasons, and a prior approval decision does not remove the wildlife legislation that applies to the works. The order to do things in is covered in our note on barn conversion bat survey sequence and seasons.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.

Browse the PlanScope report types if you want a draft prepared for the prior approval or the full application that follows it.

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