A Class Q prior approval submission checklist

A Class Q prior approval submission is not a planning application, and treating it like one is the fastest way to lose it. The council is not deciding whether houses in the countryside are a good idea. It is deciding a closed list of matters set out in Part 3 of Schedule 2 to the General Permitted Development Order 2015, and it has 56 days to do it. Everything in your submission should be aimed at those matters and at proving the building qualifies in the first place.

Two documents do most of the work: a structural appraisal showing the barn can be converted without being rebuilt, and evidence that the building was in sole agricultural use on the qualifying date.

What the application has to contain

The procedural requirements sit in paragraph W of Part 3, and they are short. A written description of the proposed development, a plan indicating the site, the developer's contact address and email address, and the fee. The authority can ask for further information reasonably necessary to determine the application, and in practice it will.

Beyond the statutory minimum, a submission that gets approved usually contains:

• A site location plan with the red line and the building identified.
• A block plan showing the building, the proposed curtilage and the access.
• Existing and proposed floor plans, elevations and sections at a stated scale.
• A structural appraisal by a suitably qualified engineer.
• Evidence of the agricultural use on the qualifying date.
• A short statement addressing each prior approval matter in turn.
• A flood risk position, a contamination position and a highways position, proportionate to the site.

Keep the statement to the matters listed in the Order. Arguments about housing need, local plan policy or the character of the countryside are irrelevant to a Class Q decision and including them invites the officer to treat the submission as an application.

The structural evidence, and why it decides the case

Class Q permits building works reasonably necessary for the conversion: windows, doors, roof, exterior walls, services, and partial demolition to that extent. It does not permit rebuilding. Where the works needed go beyond conversion and amount to erecting a new building inside or in place of the old one, the right is not available, and the courts have confirmed that reading.

So the structural appraisal has to answer one question directly: can this building, as it stands, take the conversion works without substantial rebuilding. It should describe the existing frame, walls, roof structure and foundations, identify what is being retained, state what the retained structure can carry, and say plainly whether new load paths or replacement of primary structure are needed.

Three things weaken an appraisal. A general statement that the building is "capable of conversion" with no analysis behind it. A schedule of works that quietly includes replacing the frame. And a report that is silent on foundations, which is where officers look when they suspect a rebuild. A Structural Survey is a report councils normally expect from a suitably qualified engineer, and professional review before submission is strongly advised. PlanScope drafts the structure and flags the site facts only an inspection can supply.

Where the barn is a steel portal frame clad in fibre cement, say so early and address the cladding replacement head on. Those buildings often pass the structural test comfortably and fail on design instead.

Drawings and the curtilage plan

The curtilage plan is the drawing most often wrong. Since the 2018 amendment, the curtilage that comes with a Class Q conversion is limited to an area no larger than the ground area of the building itself. A generous garden drawn around a small barn is outside the right, and an officer who spots it will refuse on that basis alone.

Draw the curtilage as a measured area with the figure stated on the plan, alongside the footprint figure it has to match or fall below. Then show separately, and label clearly, any land you intend to apply for later by planning application, so there is no suggestion you are claiming it under Class Q.

On the building drawings, show the existing dimensions accurately and keep the proposal inside them. The works must not extend beyond the external dimensions of the existing building, so a proposal with a dormer breaking the roof plane or a porch projecting past the wall line needs rethinking or a separate application. A design and access statement for a barn conversion is not required under Class Q, but the thinking it contains about openings, materials and the agricultural character of the building is what answers the design matter.

Answering each prior approval matter

Take them in the order the Order lists them, with a heading for each. The matters are transport and highways impacts, noise impacts, contamination risks, flooding risks, whether the location or siting makes the change of use impractical or undesirable, and the design or external appearance of the building.

Transport and highways. Deal with the existing access, visibility in both directions, the surface and width of the track, turning within the site and parking. Where the access serves a working farm as well, say how the uses will share it.

Noise. The question is usually noise affecting the new dwellings rather than noise from them: a grain dryer, a livestock building, a road or a poultry unit nearby. Identify the source and the separation distance.

Contamination. Former sheep dips, fuel and oil tanks, pesticide stores, asbestos cement sheeting and made ground under yards are the recurring issues. Where there is a credible source, a Land Contamination assessment prepared in accordance with the relevant British Standard by suitably qualified and experienced persons is legally expected, and a drafted report is a starting point for that specialist rather than a substitute.

Flooding. Check the flood map for planning and state the zone. In Zone 2 or 3, provide a Flood Risk Assessment with finished floor levels and access and egress, and remember that a Class Q dwelling in Zone 3 is a hard case.

Location or siting. This is the catch-all, and it covers remoteness, isolation, access in winter, and whether the building sits in a working farmyard that would make residential occupation impractical. Answer it with facts about distances and the surrounding uses rather than with assertions.

Design or external appearance. Retain the agricultural character. Large glazed openings in place of cart entrances, minimal eaves detail, dark frames, no domestic paraphernalia, and a hard surface rather than a lawn to the frontage.

The 56 day period and deemed approval

The authority has 56 days from receipt of a valid application to notify its decision. If it does not, the development may proceed in accordance with the submitted details. That is a real right, not a technicality, and it is why the quality of the submitted drawings matters so much: whatever is deemed approved is whatever you sent in.

Three cautions. The 56 days run from a valid application, so an incomplete submission or an unpaid fee resets the clock. The authority may carry out consultation and neighbour notification within the period, and the responses can prompt a refusal late in the window. And development has to be completed within three years of the prior approval date.

Where drainage is part of the proposal, get it resolved inside the period rather than leaving it to building control. A drainage strategy for a minor residential scheme on a rural site usually means a package treatment plant with discharge consent considerations, and that affects the siting of the curtilage.

Evidence of the agricultural use

The building must have been used solely for agriculture, as part of an established agricultural unit, on 20 March 2013, or for ten years before the change of use where the agricultural use began later. It must not be listed or a scheduled monument, must not sit on land excluded from the right such as a National Park, National Landscape, conservation area, World Heritage Site or site of special scientific interest, and must not have been erected under agricultural permitted development within the previous ten years.

Evidence that persuades:

1. Rural payments and subsidy records naming the holding and the parcels.
2. Dated invoices for feed, fertiliser, seed, veterinary services or contracting.
3. Herd or flock records, movement records and machinery registration documents.
4. Tenancy agreements or farm business tenancies covering the qualifying date.
5. Dated photographs and aerial imagery, including historic imagery showing the building in agricultural use.
6. A statutory declaration from the owner or a former occupier, used to tie the documents together rather than to substitute for them.

Note the limits on numbers and floorspace. The Order was amended in 2024 and now permits a larger number of dwellings and a higher cumulative floorspace than the original version, with a cap on the size of each dwelling. Check the current text of Class Q before you fix the unit mix, because this is the provision most likely to have changed since any guide you are reading.

The checklist

Work through this before you submit:

1. Confirm the qualifying date evidence and that no exclusion applies to the land.
2. Confirm the building was not erected under agricultural permitted development in the last ten years.
3. Measure the building footprint and draw the curtilage at no more than that area.
4. Commission the structural appraisal and read it critically for anything amounting to rebuilding.
5. Check the flood zone and the contamination history.
6. Draw existing and proposed within the existing external dimensions.
7. Write one short section per prior approval matter, in the Order's sequence.
8. Check the numbers against the current version of Class Q.
9. Pay the correct fee and diarise day 56.

Enter your postcode on PlanScope to see which supporting 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 are lawful. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.