Agricultural prior notification or prior approval

Farmers talk about sending in a prior notification for a new building. The Order does not use that phrase. What Part 6 of Schedule 2 to the General Permitted Development Order 2015 requires is an application to the local planning authority for a determination as to whether prior approval will be required for the siting, design and external appearance of the building. So agricultural prior notification or prior approval are two stages of one process, and confusing them is what leads to buildings put up in the wrong place.

Stage one asks the authority whether it wants to control the details. Stage two, which happens only if the answer is yes, is the authority approving or refusing those details. Most applications stop at stage one, which is why the whole thing gets called a notification.

What Part 6 permits on an agricultural unit

Part 6 gives agricultural rights in two classes. Class A applies to agricultural units of 5 hectares or more and permits, within limits, the erection, extension or alteration of a building and related works reasonably necessary for agriculture within the unit. Class B applies to units of less than 5 hectares and permits extensions and alterations to existing buildings plus tracks, hard surfaces, plant, waste deposit and water works, with no new buildings.

Neither class permits a dwelling. Neither covers equestrian use beyond grazing, because keeping horses for recreation is not agriculture. And neither authorises anything on land that is not part of the agricultural unit.

The limits that most often bite are the 1,000 m² ground area cap for a building, the 12 metre height limit reducing to 3 metres within 3 kilometres of an aerodrome, the 25 metre standoff from the metalled part of a trunk or classified road, and the 400 metre separation for livestock accommodation and slurry storage from the curtilage of a protected building.

The notification stage, in detail

The application for a determination is short but specific. It needs a written description of the proposed development, the materials to be used, a plan showing the site, and the fee set in the fee regulations, which is indexed annually.

Three outcomes follow.

The authority may notify you that prior approval is not required. You then build in accordance with the details you submitted.

The authority may notify you that prior approval is required, which starts stage two.

Or the authority may say nothing. Where 28 days pass from receipt without the authority notifying you of its determination, you may proceed in accordance with the submitted details. Silence is an outcome, and it is the outcome that most often causes trouble later, because the submitted details become the scheme you are permitted to build and people treat them as a sketch.

Where prior approval is required

The matters that can be reserved for approval differ by the type of development, which is a detail worth knowing because it tells you what the authority can and cannot control.

Note the limits on that control. For a building, the authority can require you to move it, change its cladding colour or alter its roof form. It cannot use prior approval to refuse the principle of an agricultural building, and it cannot use it to impose conditions about hours of use, drainage or landscaping unrelated to those reserved matters. Authorities sometimes try, and a politely worded reminder of the scope usually resolves it.

Extensions and alterations only need the determination route where they cross the threshold the Order sets, defined by an increase in the cubic content of the original building beyond a stated percentage or an increase in its height. Below that threshold the work proceeds without any application.

Unit size thresholds and the cumulative area limit

Two numbers drive whether Part 6 is available at all.

The 5 hectare line separates Class A from Class B, measured across the agricultural unit, which can include several parcels in the same occupation including rented land.

Then there is a cumulative area control in Class A that catches farms building steadily over several years. The ground area covered by the proposed building or works is aggregated with development carried out under the same class within a stated distance and a stated recent period, and the total is capped at 465 m². Read the current text and the interpretation paragraph before you design, because the aggregation rule is the provision most often overlooked and the most likely to render a notification invalid.

Where the aggregate is exceeded, the answer is a full planning application rather than a redesign, and the application is usually granted on functional need grounds if the siting and scale are right.

Conditions and the longer-term rules

Part 6 rights come with conditions that bind after the building is up.

Development for which a determination was sought must be started within five years of the authority's determination, and it must be carried out in accordance with the approved details, or the submitted details where approval was not required.

The building has to be used for agriculture. Part 6 also contains provisions dealing with what happens where agricultural use ceases within a period after the building is erected, which can require its removal and the restoration of the land if permission for another use is not granted. Anyone planning to build now and convert later should take advice first, because a building put up under Part 6 sits awkwardly with the conversion rights people assume will be available.

Additional restrictions apply on designated land, including National Parks, the Broads, National Landscapes and conservation areas, and rights can be removed by an Article 4 direction or by a condition on an earlier permission.

Where full permission becomes necessary

Five situations, and each is a normal application rather than a problem.

1. The unit is under 5 hectares and the proposal is a new building.
2. The cumulative area cap is exceeded.
3. The proposal is within 400 metres of a protected building and involves livestock or slurry.
4. The use is not agriculture, including most equestrian activity and any diversification enterprise.
5. The building is a dwelling, which Part 6 never permits.

In each case a Planning Statement setting out the functional need, the alternatives considered and the siting logic carries the application. Where the site is prominent or designated, add a Landscape and Visual Impact Assessment. Where the proposal takes higher quality farmland out of production, an Agricultural Land Classification assessment may be requested, and that is work councils expect from a suitably qualified soil specialist, so professional review is strongly advised.

Preparing the notification correctly

Treat the submission as the drawing you will build from.

• A site plan at a stated scale showing the building, the unit boundary, the nearest protected buildings with distances, and any road within 25 metres.
• Elevations and a plan of the building with dimensions and ridge height.
• A materials schedule with colours specified, because colour is within the authority's control and a supplier substitution later is a breach.
• A short note on why the building is reasonably necessary for agriculture within the unit, with stock numbers, tonnage or machinery to be housed.
• A statement of the unit area, and of any development carried out under the same class in the recent period, with areas.

One honest uncertainty: authorities vary in how readily they decide that prior approval is required, and some treat almost every building as needing design control while others rarely do. Ask the rural or countryside officer before you submit, and if silence looks likely, make sure the submitted details are ones you are content to be held to.

Enter your postcode on PlanScope to see which reports your site 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.