Quick Answer

What Is Class Q?

Class Q (Change of use of an agricultural building to a dwellinghouse) was introduced in 2014 and significantly expanded in subsequent amendments. It falls under Part 3 of Schedule 2 to the GPDO 2015, which deals with changes of use.

Unlike Part 1 permitted development rights for houses, Class Q always requires a Prior Approval application. Prior Approval is a form of consent where the council can only assess the specific matters listed in the legislation — it cannot refuse on general amenity grounds or raise issues outside the permitted scope.

Class Q has been used extensively to convert redundant farm buildings across England into rural homes. It has proved controversial in some areas, with councils concerned about the proliferation of rural dwellings on agricultural land without normal planning scrutiny.

Eligibility Criteria

• Agricultural use before 20 March 2013: The building must have been used for agricultural purposes on or before 20 March 2013, or if built after that date, in agricultural use for at least 10 years
• Not a listed building: The building must not be listed or within the curtilage of a listed building
• Not in a safety hazard area
• Structural suitability: The building must be structurally capable of functioning as a dwelling with only the works permitted under Class Q — the existing structure must be capable of conversion without extensive rebuilding
• No previous Class Q use: The cumulative total of dwellings from agricultural buildings on the agricultural unit must not exceed the limits

The Prior Approval Process

A Prior Approval application is submitted to the local planning authority and typically requires: a site location plan, existing and proposed floor plans and elevations, a statement demonstrating eligibility, details of any structural works, a transport and access statement, contamination assessment, flood risk assessment if relevant, and a noise assessment if needed.

The council has 56 days to determine a Prior Approval application. If it doesn’t respond within this period, approval is deemed to be given. The council can only refuse on the specific matters it’s permitted to assess.

Size Limits and Number of Dwellings

A single large agricultural building can therefore be converted into up to 5 separate homes, provided each is no more than 465m² and the total across the unit doesn’t exceed the cumulative limit. In practice, most barn conversions under Class Q create 1 to 3 dwellings.

What Works Are Allowed

Class Q permits both the change of use and certain building operations to convert the building. The permitted operations include: installation of windows, doors, rooflights, and solar panels; insulation; installation of services; partial infilling of openings; creation of internal walls; and reasonable external alterations needed for residential use.

Structural rebuilding of the main structure, creation of significant new floor area, and extending the building beyond its existing footprint are not permitted. Class Q is a change of use right, not a rebuilding right.

Why Applications Get Refused

• Building not structurally capable: The council considers the building too derelict to be converted without extensive rebuilding beyond Class Q’s permitted operations
• No evidence of agricultural use pre-March 2013
• Flood risk or contamination concerns not adequately addressed
• Transport/highway safety concerns
• Cumulative limit exceeded