Class MA after the removal of the size and vacancy limits

Since 5 March 2024 Class MA has had no floorspace cap and no vacancy requirement. A whole commercial building can convert to housing under prior approval, and it can do so while the tenant is still trading. The two year rule survived: the building must have been in a use falling within Class E for a continuous period of at least two years before the date of the prior approval application.

The change came in the Town and Country Planning (General Permitted Development and Use Classes) (Amendment) (England) Regulations 2024. This summary is as at September 2026, and the underlying right sits in Schedule 2, Part 3, Class MA of the General Permitted Development Order 2015 as amended.

What actually changed and what did not

Removing the cap matters most on office buildings, where the previous limit forced awkward part conversions or a full planning application. Removing the vacancy rule matters most commercially, because a landlord no longer has to empty a building and carry three months of void before applying.

That second change is why Article 4 direction activity increased. A council that wants to protect trading shops or occupied offices now has one main tool, and directions are site-specific and published, so check the register before you underwrite a deal.

The two year use test still bites

The building has to have been in a Class E use for a continuous period of at least two years before the application date. Two situations catch people out.

A building that has been empty for years may struggle, because the use has to have subsisted in the relevant period. Long-term vacant retail is the classic problem, and the evidence has to come from somewhere: rating records, lease documents, utility accounts, dated photographs.

A building whose use has moved in and out of Class E does not accrue a continuous period. Storage and distribution at Class B8, and any sui generis use such as a pub or a hot food takeaway, break the continuity.

Assemble the evidence before applying. The prior approval is refused if the right does not apply, and the fee is not refunded.

The prior approval matters

Prior approval under Class MA is not a formality. The council may only consider the matters listed in the Order, but that list covers most of what makes a bad conversion.

• Transport and highways impacts, particularly parking and servicing.
• Contamination risks on the site.
• Flooding risks on the site.
• Impacts of noise from commercial premises on the future residents.
• Where the building is in an area the authority considers important for general or heavy industry, storage and distribution or waste management, the impact on the intended occupiers.
• Where the building is in a conservation area, the impact of the loss of a ground floor use.
• Provision of adequate natural light in all habitable rooms.

Natural light is the one that kills schemes on deep floorplates. Every habitable room needs a window, which on a large office floor means either a light well, a reduced unit count, or a layout with very deep single aspect flats that fails the test anyway.

Noise is the second. Where the building sits above or beside a pub, a takeaway, a gym or a plant deck, a Noise Impact Assessment that addresses internal levels against the relevant standard is what turns an objection from environmental health into a condition. Councils usually expect a suitably qualified author for acoustic work.

Contamination and flooding follow the same pattern. A Contaminated Land Assessment at Phase 1 desk study level answers the contamination point on most sites, and it must be prepared by a suitably qualified and experienced person, with a Phase 2 investigation where the desk study identifies a plausible pollutant linkage. A Flood Risk Assessment is needed where the building is in Flood Zone 2 or 3, and ground floor residential in Flood Zone 3 is difficult.

Space standards apply, and so do several other regimes

New dwellinghouses created under permitted development must meet the nationally described space standard, as a condition in the Order. That applies to Class MA regardless of whether the council has a space standard policy of its own.

Three other regimes are worth stating plainly, because assumptions about them cost money.

Biodiversity net gain does not apply to development carried out under permitted development rights, so a Class MA conversion is outside the mandatory gain regime. That is a genuine advantage over a full application on the same building.

Nutrient neutrality does apply. The habitats regulations bind the authority as competent authority whatever the route, and prior approvals have been refused in affected catchments.

Community Infrastructure Levy can apply, and the removal of the planning vacancy rule does nothing to the levy's own in-use building test. Relief for existing floorspace depends on the building having been in lawful use for a continuous period of at least six months within the preceding three years, measured on the levy's own terms. A building emptied to suit a marketing programme can fail that test even though Class MA no longer cares about vacancy.

Procedure and timescales

The application goes in with the prescribed information, a plan of the site, the floor plans, and the evidence on the two year use. The determination period is 56 days from the day after a valid application is received, and if the authority does not notify a decision within that period the development may proceed in accordance with the application.

Do not treat the 56 day deemed approval as a strategy. An invalid application never starts the clock, and disputes about validity are the usual reason a deemed consent argument fails.

Development has to be completed within three years of the date of prior approval. On a large building that is a real constraint, and it should sit in the programme alongside the funding.

Illustrative example. An investor buys a 2,400 m² office let to two tenants on leases expiring in eighteen months. Under the current rules the size and vacancy tests are no obstacle, so the prior approval can be applied for now. The scheme then fails on natural light in the central core, and the deliverable count drops once a light well is designed in. This example is illustrative only.

Due diligence before you commit

1. Check the Article 4 register for the area, and the date any direction takes effect.
2. Confirm the building is not listed, within the curtilage of a listed building, a scheduled monument or otherwise excluded land under the class.
3. Evidence two years of continuous Class E use immediately before the intended application date.
4. Test natural light and the space standard on a real layout before agreeing a price.
5. Check the flood zone, the contamination history and whether the site is in a nutrient catchment.
6. Model the levy position on the in-use building test rather than assuming relief.

A Planning Statement is not required for prior approval, though a short covering note that walks the officer through each prior approval matter, with the evidence attached, is the difference between a clean 56 days and a request for further information at day 40.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it, and remember that a lawful development certificate is the only formal way to confirm that works or a use are lawful.

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