Office to Residential Conversion Under Permitted Development

What This Requirement Covers

Class MA of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) allows the change of use of commercial, business, and service buildings (Use Class E) to residential use (Use Class C3) without full planning permission, subject to prior approval from the local planning authority.

Key Requirements

Key Conditions

1. The building must have been in Use Class E (or its predecessor classes) for at least 2 continuous years before the date of the prior approval application
2. The building must have been vacant for at least 3 continuous months before the application
3. The cumulative floor space being changed must not exceed 1,500 m2 (no minimum size)
4. The building must not be listed or in a scheduled monument
5. The building must not be in a safety hazard zone, military explosives storage area, or SSSI

Prior Approval

The local planning authority assesses the following matters

1. Transport and highways impacts
2. Contamination and flooding risks
3. Noise from commercial premises affecting the intended residential use
4. The provision of adequate natural light to all habitable rooms
5. The impact on the sustainability of an area's shopping function (for ground-floor commercial premises)
6. Fire safety (where the building is 18 metres or more in height)

Building Regulations

1. Full Building Regulations compliance is required, regardless of the planning route
2. Key areas of compliance include:

- Fire safety (Part B): Conversion to residential triggers full compliance with Approved Document B for the new use - Sound insulation (Part E): Separating walls and floors between new dwellings must meet Part E standards - Energy efficiency (Part L): Thermal elements must be upgraded to renovation standards - Ventilation (Part F): Each dwelling must have adequate ventilation - Accessibility (Part M): The requirements of M4(1) apply as a minimum

Limitations

1. Prior approval may be refused on the matters assessed
2. Some local authorities have used Article 4 directions to remove Class MA permitted development rights in certain areas
3. The permitted development right does not authorise external alterations (a separate planning application may be needed for new windows, doors, or other external changes)

Practical Compliance Tips

1. Check that the building meets all the preconditions (use class, vacancy period, floor area, heritage status) before applying
2. The prior approval application fee is currently GBP 100 per dwelling
3. Submit a noise assessment if the building is near commercial or industrial premises; this is a common reason for refusal
4. Ensure all habitable rooms have adequate natural light; windowless rooms cannot be used as bedrooms or living rooms
5. Budget for significant Building Regulations compliance work; most offices need substantial upgrades for fire safety, sound insulation, and energy efficiency
6. Appoint a building surveyor to assess the building for conversion feasibility before purchase
7. Class MA does not permit external alterations; if new windows are needed, apply for planning permission concurrently