Class Q barn conversion rules are the part of the General Permitted Development Order, the GPDO, that lets an agricultural building become dwellinghouses without a planning application, subject to a prior approval from the authority on the matters the class names. What is class Q planning to a developer is a route rather than a permission: the building must have been in agricultural use on the qualifying date, the conversion must stay within caps on the number of dwellings and the total floorspace counted across the whole agricultural unit, each dwelling has its own floorspace limit, the works must be a conversion rather than a rebuild, and the class does not run on designated land. Class Q planning permission as most people search for it is the prior approval, which is not a permission but the authority's decision on transport, noise, contamination, flooding, siting and design and whether the location makes a dwelling impractical. This page sets out the rules as the developer reads them at the barn, and the class Q permitted development barn conversion sheet on this site works the caps from your figures.
The qualifying date and the use that counts
The building must have been used solely for an agricultural use as part of an established agricultural unit on the qualifying date the class names, or for ten years before it if it was not in use then, and a building that has been a workshop, a store for a haulage firm or an equestrian yard has left the class whatever the vendor says. The class Q barn conversion rules also exclude buildings on designated land, listed buildings and scheduled monuments, and a holding that has used other agricultural classes recently. The history is the holding's, and the sheet on this site takes it as an input rather than reading it.
The caps, per holding and per dwelling
The class caps the dwellings and the cumulative floorspace per agricultural unit, counting every conversion the unit has already made under it, and it limits the floorspace of each dwelling made. A large barn on a holding that converted another building three years ago may have no headroom at all, and a barn that fits the floorspace cap may support fewer dwellings than the particulars promise once the per-dwelling limit is read. The class Q sheet returns the floorspace per dwelling, the headroom on the holding and the dwellings the floorspace supports at the limit, which are the three figures an offer on a barn is built from.
Conversion, the extension and what prior approval decides
The works must be reasonably necessary to convert the building and may not amount to rebuilding: a portal frame that needs new walls, a new roof and new foundations is a new building and the class does not apply, which is why the engineer's report comes before the offer. Since the class was widened it allows a single-storey rear extension of limited depth on a hard surface that existed on the qualifying date, and the sheet reads that area from the wall you enter. Prior approval then decides the matters the class names, and a refusal on siting and design or on the location being impractical for a dwelling is common on remote barns; the order cited below sets every figure, and Curtilo Pro keeps the reading against the building and the holding.
Questions people ask about class q barn conversion rules
Is class Q planning permission?
No. It is a permitted development right subject to prior approval: the authority decides the named matters and cannot refuse on others, but a scheme outside the caps, on designated land or amounting to a rebuild has no right at all and needs a planning application.
How many dwellings does class Q allow?
A capped number per agricultural unit within a capped total floorspace, each dwelling within its own floorspace limit, all counted with what the unit has already converted. The sheet on this site reads the headroom from your figures; the order cited below states the caps and the date they last changed.
Does class Q apply in a national park or a conservation area?
No. The class does not run on article 2(3) land, which includes national parks, areas of outstanding natural beauty, conservation areas and the Broads, nor on listed buildings. A barn there is a planning application, and the guide on permitted development in a conservation area sets out what designation removes.
Sources
- legislation.gov.uk, GPDO 2015 Schedule 2 Part 3: changes of use, including class Q (agricultural buildings to dwellinghouses) and class R (agricultural buildings to flexible commercial use)
- GOV.UK planning practice guidance, When is permission required: development, permitted development rights, prior approval and article 4 directions
- GOV.UK, Permitted development rights for householders: technical guidance, the government's reading of Part 1 with diagrams of the original house, the rear and side limits and designated land