Proving the qualifying use for a Class Q barn conversion
The Class Q qualifying use test decides most barn conversion prior approvals before design is ever discussed. This is what the Order asks you to prove, and the paperwork that proves it.
Class Q turns on a use test before anything else. The building must have been used solely for agriculture, as part of an established agricultural unit, on 20 March 2013. If it was not in agricultural use on that date, it must have been in that use for at least ten years before the day the conversion begins. The Class Q qualifying use test is where a case officer starts, and no amount of good design rescues an application that fails it. So assemble the evidence before you draw a plan.
What Class Q asks you to prove
Class Q sits in Schedule 2, Part 3 of the Town and Country Planning (General Permitted Development) (England) Order 2015, as amended by the Town and Country Planning (General Permitted Development etc.) (England) (Amendment) Order 2024. It gives a right to change agricultural buildings to dwellinghouses, and a linked right to carry out the building operations reasonably necessary for that change.
Three phrases in the qualifying conditions do almost all the work.
The first is solely. The Order does not say mainly, or predominantly. A building shared between hay storage and a joinery business does not qualify, however small the joinery corner.
The second is agricultural use. Agriculture is defined at section 336(1) of the Town and Country Planning Act 1990 and covers horticulture, fruit growing, seed growing, dairy farming, the breeding and keeping of livestock, grazing land, meadow land, market gardens and nursery grounds. Horses kept for riding, livery or competition are outside that definition, which is why so many stable blocks fail at the first hurdle.
The third is established agricultural unit, meaning agricultural land occupied as a unit for the purposes of agriculture either on or before 20 March 2013, or for the ten years running up to the development. A barn standing alone on a paddock sold off from a farm twenty years ago may not sit on an agricultural unit at all.
The 20 March 2013 date and the ten year alternative
The date was fixed when the right was first introduced, to stop people erecting agricultural buildings purely to convert them. It is a snapshot test rather than a continuous one, and that cuts both ways. You do not have to show unbroken agricultural use from 2013 to today. But you do have to show the position on that specific date.
Where the building was in agricultural use before 20 March 2013 and standing empty on it, the Order looks back to when it was last in use. Empty is not fatal. Converted to a workshop in 2011 is.
Buildings that came into agricultural use after the date are treated under the ten year rule, and the clock is counted back from the day the conversion work starts rather than from the date of the application. A barn first used for agriculture in the spring of 2017 therefore reaches eligibility in 2027, not before.
Evidence that carries weight
Officers want documents that were created for another purpose at the time, not statements written for the application. The strongest packs combine several independent record trails covering the same years.
| Evidence | What it establishes |
|---|---|
| Rural Payments Agency records, holding (CPH) number, land parcel maps | The land was occupied as an agricultural unit on given dates |
| Cattle passports, sheep and goat movement records, holding registers | Livestock were kept on the holding in the relevant years |
| Farm accounts, VAT returns and tax computations | The enterprise traded as a farm across the period |
| Invoices for feed, seed, fertiliser, veterinary work and contracting | Ordinary agricultural activity, dated and addressed to the holding |
| Agricultural tenancy or grazing licence documents | Occupation for agriculture, and who held it |
| Insurance schedules naming the building and its contents | The building itself was in agricultural use |
| Dated photographs and historic aerial imagery | Machinery, stock or crop in and around the building |
One check is worth running early. Buildings in agricultural use are exempt from business rates, so ask the council for the rating history of the site. A rating entry describing the building as a store, workshop or warehouse in 2012 will surface during the officer's own checks, and it is better to know about it first.
Buildings put up or brought into use after the qualifying date
The Order also restricts Class Q where agricultural permitted development has been carried out on the same established agricultural unit within the preceding ten years. Farmers who put up a new grain store under Part 6 and then look at the old Dutch barn next to it are often caught by this, so audit the whole holding rather than the single building.
Tenancies matter too. Where the site is held under an agricultural tenancy, Class Q requires the tenancy position to be resolved before the right can be used, and the application form asks you to certify it. Sort that with the landlord or tenant in writing at the outset, because a late objection from the other party stops the application dead.
Where a mixed or lapsed use defeats the claim
Diversification is the usual culprit. A barn part let for caravan storage, a corner used to sell farm produce to the public, a bay converted to a workshop for the farm's contracting arm: each introduces a non-agricultural element into the period being relied on.
The response depends on the geometry. Where the other use occupied a physically separate part of the building, some applicants draw the red line tightly around the part that was only ever agricultural and accept a smaller scheme. Where the mixed use ran through the whole building, Class Q is not the route, and a full planning application is the honest alternative.
Lapsed use is the other pattern. If the holding was broken up and the land ceased to be occupied as an agricultural unit well before 2013, the building may have no qualifying use to point back to, even though everyone locally still calls it a barn.
Building the statutory declaration pack
Documents rarely cover every year, and statutory declarations fill the gaps. A declaration is made under the Statutory Declarations Act 1835 before a solicitor or commissioner for oaths, and its value comes from first-hand knowledge rather than from the formality.
- Identify the declarants: the owner or farm manager, and at least two independent people such as the contractor who baled, the vet, the feed merchant or the neighbouring farmer.
- Give each declarant the years you need covered and ask them to describe what they personally saw or did, not what they believe about the planning position.
- Exhibit the supporting documents to the declaration and cross-reference them, so an officer can follow a claim about 2012 straight to the invoice that supports it.
- Keep opinion out. A sentence saying the building has always been agricultural adds nothing and invites a challenge to the whole declaration.
- Have them signed and dated before submission, not promised.
An illustrative example: a steel-framed Dutch barn on a 45 hectare arable holding, used for straw and machinery storage, might be supported by twelve years of payment scheme records, contractor invoices for baling in each harvest year, an insurance schedule listing the barn, and declarations from the owner and the baling contractor. That pack answers the qualifying use question without the officer having to ask a single follow-up.
What to submit with the prior approval application
Send the evidence as a properly ordered bundle with a contents schedule, not as a folder of scans. Alongside it, the application normally carries a site location plan showing the extent of the agricultural unit, existing and proposed floor plans and elevations, and a structural appraisal confirming the building can take the conversion without effectively being rebuilt.
The prior approval matters themselves also need covering, and the ones that generate the most correspondence are highways access, noise from nearby agricultural operations, land contamination and flood risk. Where the barn has held fuel, fertiliser or sheep dip, expect the officer to ask for a contamination assessment. Where any part of the site sits in Flood Zone 2 or 3, a flood risk assessment will be expected with the submission rather than after it.
A short planning statement pulling the qualifying use argument together, with the evidence schedule as an appendix, saves the officer from reconstructing your case. Councils have 56 days to determine a Class Q prior approval, and an incomplete evidence pack is the quickest way to lose that clock to a request for further information.
Enter your postcode on PlanScope to see which supporting reports a barn conversion site is likely to need before you submit.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it, and remember that a lawful development certificate is the only formal way to confirm that works are lawful. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
What date does Class Q use to test agricultural use?
The building must have been in sole agricultural use, as part of an established agricultural unit, on 20 March 2013. If it was not in use on that date but had been used for agriculture earlier, the test looks at the last use before it fell empty. Buildings first brought into agricultural use after that date need ten years of qualifying use instead.
Does a stable block qualify for Class Q?
Usually not. Agriculture under section 336(1) of the Town and Country Planning Act 1990 covers the breeding and keeping of livestock, but horses kept for riding, livery or recreation are not livestock for that purpose. A building used for grazing horses on land kept as meadow may sit differently, so the actual use has to be evidenced rather than assumed.
How much evidence does a council expect?
Enough to satisfy the officer on the balance of probabilities. In practice that means documents rather than recollection: payment scheme records, movement books, accounts and invoices spanning the relevant period, supported by statutory declarations from people with first-hand knowledge. Precise and unchallenged evidence is normally accepted, while a single signed letter rarely is.
Can I convert a barn I built five years ago?
Not yet under Class Q. A building brought into agricultural use after 20 March 2013 needs at least ten years of sole agricultural use behind it, counted back from the day the conversion work starts. The Order also restricts Class Q where agricultural permitted development has been carried out on the same unit recently, so check the holding's history first.
What happens if part of the barn was used for something else?
The word in the Order is solely, so a genuine mixed use during the relevant period defeats the claim for that part of the building. Some applicants respond by drawing the application red line around the part that was only ever agricultural. Others apply for full planning permission instead, where a mixed history is a material consideration rather than a bar.
Sources and further reading
- The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2 Part 3
- The Town and Country Planning (General Permitted Development) (England) Order 2015
- Planning Practice Guidance: when is permission required
- Town and Country Planning Act 1990, section 336 interpretation
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.