Class Q: proving the building was in agricultural use

Class Q prior approvals are refused more often on the agricultural use question than on anything to do with structure or design. The class requires the building to have been in agricultural use as part of an established agricultural unit on 20 March 2013, or, if it was not in use on that date, when it was last in use. A building brought into agricultural use after that date has to show ten years of such use before the application. Those are the tests, and the burden of proving them sits squarely with the applicant.

The qualifying date the class uses

20 March 2013 is the date written into Class Q of Part 3 of Schedule 2 to the General Permitted Development Order 2015. It is not the date the class came into force and it has no significance beyond being the line the drafters drew.

Three limbs follow from it.

If the building was in agricultural use on 20 March 2013, as part of an established agricultural unit, the test is met. If it was not in use at all on that date, the question becomes what it was last used for before then, and agricultural use answers it. And if the building came into agricultural use after 20 March 2013, it must have been used that way for at least ten years before the application is made.

That third limb is the one that catches recent purchasers. Buying a barn in 2021 and putting hay in it does not start a clock that has already been running since 2013 for somebody else's building. It starts a new ten year period.

What counts as agricultural use

Agriculture takes its meaning from section 336 of the Town and Country Planning Act 1990, and the definition is broad but closed. It covers horticulture, fruit growing, seed growing, dairy farming, the breeding and keeping of livestock, the use of land as grazing land, meadow land, osier land, market gardens and nursery grounds, and woodlands ancillary to the farming of land.

Livestock in that definition means creatures kept for the production of food, wool, skins or fur, or for use in the farming of land. A working farm horse is caught. A riding horse is not.

Established agricultural unit means agricultural land occupied as a unit for the purposes of agriculture. The building has to be part of that unit, which means a barn sold off separately years ago, with no land, raises a question before anyone looks at the use.

Uses that look agricultural and are not

This is where applications fail, and the pattern is consistent.

• Equestrian use. Keeping, riding or training horses is not agriculture. A livery yard is not an agricultural use and a stable block is generally not an agricultural building.
• Storage for a non-agricultural business. A barn full of a groundworks contractor's plant and materials is in storage use, whatever the roof is made of.
• Farm shops selling substantial bought-in goods, which can be a retail use rather than an ancillary agricultural one.
• Buildings converted to workshops, offices or holiday storage at some point in the past, where the agricultural use ended before the qualifying date.
• Redundant buildings on land that stopped being farmed decades ago, where the last use is too remote to evidence.

Where a building has had mixed use, identify what was happening on the qualifying date specifically. A shed used half for hay and half for a joinery business is arguable. A shed used for hay until 2009 and for the joinery business since is not.

Evidence a council will accept

The council is looking for independent, dated material. A statement from the applicant is the weakest possible form of evidence and should never be the only one.

Aerial imagery deserves particular attention because it is independent and dated. Images from around March 2013 showing a farmyard in active use, with the building in question part of it, do more work than three pages of narrative.

Statutory declarations are useful but only as corroboration. A declaration from a neighbouring farmer who bought hay from the building every summer for fifteen years, naming dates, is evidence. A declaration saying the building "has always been used for farming" is not.

Buildings erected under agricultural permitted development

Where the barn was itself built under the agricultural permitted development rights in Part 6, check the conditions attached to that class before applying under Class Q. Those rights come with restrictions on changing the use of the building within a period after it was erected, and a conversion inside that period will not be permitted development.

This matters more than it used to, because steel portal frame buildings erected under prior notification in the 2010s are now reaching the age where owners start thinking about conversion. Get the prior notification records from the council's planning history before assuming the route is open.

Assembling the evidence pack

Present it as a case rather than a bundle.

1. A short statement of the agricultural use history, with dates, written as a chronology.
2. A plan showing the building, the curtilage and the extent of the agricultural unit as it was on the qualifying date.
3. The documentary evidence, indexed and cross-referenced to the chronology.
4. Dated photographs and aerial imagery, with sources and dates on each image.
5. Statutory declarations, where used, naming specific years and activities.
6. The planning history of the building, including any prior notification under Part 6.

Submit it with the prior approval application rather than waiting to be asked. The determination period for a Class Q prior approval is short, and an authority that has to write out for evidence will usually refuse rather than run out of time.

Two other Class Q issues are worth checking at the same time. Flood zone restrictions apply to the class, and the article on flood zone restrictions on Class Q and Class MA covers where the route closes. And conversions under prior approval can attract a levy charge, dealt with in the note on community infrastructure levy on prior approval schemes.

The floorspace and unit number limits in Class Q were amended in 2024, so read the current text of the Order rather than an older summary before you fix the number of dwellings.

What happens if the evidence is thin

Two routes remain, and both are slower.

Apply for a lawful development certificate for the existing use first, establishing the agricultural use as a matter of fact, then apply under Class Q with the certificate in hand. This is worth doing where the evidence exists but is contested.

Or apply for full planning permission for the conversion, making the case on rural housing and heritage or landscape grounds under the development plan. That takes longer and has no presumption behind it, but it is not constrained by the qualifying date at all.

A supporting Planning Statement drafted with AI assistance can set out the policy framework and the structure of the evidence case quickly, and will flag the facts and dates it does not hold rather than filling them in. The evidence itself has to come from the farm records.

Enter your postcode on PlanScope to see which documents a barn conversion is likely to need.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. A lawful development certificate is the only formal way to confirm that works or uses are lawful. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.