In 2021, the government introduced Class MA permitted development rights — creating one of the most significant opportunities in UK property investment in a generation. If you own or are considering buying a vacant commercial building, Class MA may allow you to convert it to residential use without needing full planning permission.

Here is what it is, how it works, and whether it might apply to your building.

What Is Permitted Development?

Permitted development rights are granted by national government, not by local planning authorities. They allow certain types of development or change of use to take place without a full planning application. The conditions are set nationally, which means a local planning authority cannot refuse based on local design preferences, character concerns, or opinion about what the area needs. They can only assess against the specific material considerations the law permits.

Key point

This is a fundamentally different type of consent from planning permission. The outcome is more predictable, the timeline is significantly shorter, and the grounds for refusal are much more limited.

What Is Class MA?

Class MA is the permitted development right that allows buildings in Class E commercial use to be converted to residential dwellings. The Class E category was introduced in 2020 and covers a broad range of commercial uses:

Offices
Retail shops
Restaurants & cafés
Financial services
Gyms & health centres
Light industrial

This breadth makes Class MA one of the most widely applicable permitted development rights available. A significant proportion of the UK's commercial building stock falls within Class E — including many of the vacant offices, empty retail units, and underperforming commercial properties currently sitting unused on high streets and business parks across the country.

What Is Not Class E?

Not every commercial-looking building qualifies. Certain uses sit outside Class E entirely — they are classed as sui generis (a Latin term meaning "in a class of its own"). Sui generis uses do not fit into any standard use class, which means they fall outside the scope of Class MA permitted development altogether.

The most common examples that catch investors out:

Hot food takeaways
Pubs & drinking establishments
Hostels & guest houses
Petrol stations
Casinos & amusement arcades
Nail bars (see below)
Nail bars — a grey area to watch

Nail bars are not automatically sui generis, but some local planning authorities treat them as such due to concerns about chemical fumes, strong odours, and ventilation requirements. If you are looking at a building that was most recently used as a nail bar, you need to confirm how the local authority classifies it before assuming Class E applies. A formal pre-application enquiry or Certificate of Lawful Use may be needed to resolve this cleanly.

A building that has been used as a hot food takeaway, pub, or other sui generis use — even if it looks like a normal high street commercial unit — does not qualify for Class MA unless its lawful use was formally Class E. Use history matters as much as appearance.

What Is Prior Approval?

Converting a building under Class MA requires prior approval from the local planning authority — but prior approval is not planning permission. The distinction matters.

Under prior approval, the local authority cannot approve or refuse the application based on the merits of the development as a whole. They can only assess against a specific, defined list of material considerations:

  • Transport and highway impacts
  • Contamination risks
  • Flood risk
  • Noise impact on future occupants
  • Natural light provision for habitable rooms
  • Impact on a local area with a high concentration of HMOs (in limited circumstances)
The 56-day rule

If the building meets the eligibility criteria and none of the material considerations present an insurmountable issue, prior approval must be granted. The local authority has 56 calendar days to decide. If they fail to respond within that window, deemed consent applies automatically.

Prior Approval vs Full Planning Permission

The difference in process — and risk — is significant.

Class MA Prior Approval
  • 56-day decision window
  • No design objections possible
  • No local character arguments
  • No social housing contributions
  • No sustainability requirements
  • Deemed consent if deadline missed
Full Planning Permission
  • 8 to 13+ weeks (often longer)
  • Design can be refused
  • Local character grounds apply
  • Social housing may be required
  • Sustainability conditions possible
  • No automatic approval if delayed