Class R: agricultural buildings to flexible commercial use

Class R lets an agricultural building change to a flexible commercial use without a full planning application, and since the May 2024 amendment the cumulative floorspace allowance per agricultural unit is 1,000 m². It is the quietest of the farm diversification rights and, for a lot of holdings, the most useful. A redundant grain store becomes a storage and distribution unit, a workshop, a farm shop, a gym or a small office, with a prior approval application rather than a planning application.

What Class R does not do is give you the building work. It changes the use. Any structural alteration, new opening, new roof or extension needs its own consent.

Class R sits in Schedule 2, Part 3 of the Town and Country Planning (General Permitted Development) (England) Order 2015, which has been amended repeatedly. Read the current consolidated text before committing to a route.

Which uses Class R permits

The right allows change from agricultural use to a flexible commercial use. Since the Use Classes Order was restructured in September 2020, the commercial uses available include Class B8 storage and distribution, Class C1 hotel use, and the broad Class E, which covers shops, food and drink for consumption on the premises, professional and financial services, indoor sport and recreation, medical and health services, creches and nurseries, offices, research and development, and light industrial processes. The 2024 amendment widened the list further, adding agricultural training among the permitted uses.

That breadth is the point. A farm can let a building to a joiner one year and a physiotherapist the next without going back to the council, because both sit within Class E.

Two qualifying conditions apply to the building itself. It has to have been used solely for an agricultural use as part of an established agricultural unit on or before 3 July 2012, or, for buildings brought into agricultural use after that date, for a defined period before the change. And the right applies to the building and land within its curtilage, not to open land generally.

The floorspace threshold and prior approval

The cumulative floorspace that can change use under Class R on any one agricultural unit is capped, currently at 1,000 m². Cumulative means across the whole unit and across time, so a 400 m² barn converted five years ago counts against the allowance today. Keep a record of what has already been used.

Prior approval is required from the local planning authority in respect of transport and highways impacts, noise impacts, contamination risks and flooding risks. Earlier versions of the Order allowed a simple notification below a lower floorspace figure, and the arrangements changed with the amendments, so check which route applies to the floorspace you are proposing.

The prior approval application is determined within 56 days. As with any prior approval, a complete submission matters, because an application the council considers invalid does not start the clock.

What flexible use means for future changes

The permitted use is a flexible one, which means the building can move between the specified uses without a further application. That flexibility is worth real money to a landlord, since a vacant unit can be marketed to a wider pool of tenants.

There is a trade-off. Once a building is in flexible commercial use under Class R, its planning status is different from a building in agricultural use, and the Order restricts the use of more than one of these rights on the same building. If the long-term ambition is residential conversion under Class Q, take advice before using Class R, because the sequence can close options that looked open.

The Order also provides for reversion to agricultural use where the flexible commercial use ceases. That is useful on a holding where a diversification venture may be temporary, and it is another reason to keep clear records of dates and floor areas.

Highways, noise, contamination and flood matters

The four prior approval matters each have a practical answer, and the council can consider nothing else.

Highways is usually the difficult one. A farm track designed for a tractor twice a day is a different proposition when a storage unit generates van movements every hour. Expect the highway officer to look at visibility at the junction with the public road, the width and surfacing of the track, passing places, turning within the site, and parking. A short Transport Statement with a swept path for the largest expected vehicle answers most of it.

Noise depends on the proposed use and the distance to the nearest dwelling, including the farmhouse. A joinery workshop with an extraction system is a noise case. A self-contained office is not.

Contamination is a live issue on farm buildings. Fuel tanks, sheep dip, pesticide stores, asbestos cement roofing and old workshop floors all turn up. Where the proposed use involves people spending long periods in the building, a Phase 1 desk study is the sensible starting point, and the local planning authority expects reports prepared in accordance with BS 10175 by suitably qualified and experienced persons. A Contaminated Land Assessment drafted from structured site data is a starting point for that professional rather than a substitute for their judgement.

Flooding is a map check first. If the building is in Flood Zone 2 or 3, the vulnerability of the proposed use matters, and a storage building is treated differently from a nursery.

Interaction with Class Q on the same holding

Farms often want both: houses from the stone barn and workshops from the modern shed. The Order sets limits on combining rights, and the floorspace used under one right can affect what remains available under another on the same unit.

Plan the whole holding before using any right on any building. Draw a plan showing every building, its floor area, its current use, the date it was last in agricultural use, and any permitted development already used. That one drawing will tell you more about the options than a year of speculation.

Where the plan shows that the valuable outcome needs both rights, or needs works Class R does not permit, a full planning application for a mixed farm diversification scheme is often the better route. It carries a fee and an eight-week determination period, but it can be shaped rather than fitted to a fixed set of limits, and a Planning Statement can set out the rural economy case that national policy supports.

Reverting to agricultural use afterwards

Reversion sounds simple and is worth thinking through before the tenant fit-out starts. A building converted to a food preparation unit with drainage, three-phase power and an insulated internal skin is not readily returned to grain storage, whatever the planning position allows.

Two practical habits help. Write the lease so that the tenant's alterations are removable and reinstatement is a tenant obligation. And keep the paperwork: the prior approval decision, the notification correspondence, dated photographs of the building before conversion, and a running tally of floorspace used against the allowance.

If a lawful development certificate is later needed to prove the use, that file is what proves it.

Enter your postcode on PlanScope to see which supporting reports a farm diversification scheme on your holding is likely to need, then check the list against your council's validation requirements.

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