Agricultural prior notification or full planning permission

The deciding question is the size of the agricultural unit. On a holding of five hectares or more, Part 6 of Schedule 2 to the General Permitted Development Order 2015 allows new agricultural buildings within limits, subject to a prior notification procedure. Below five hectares there is no permitted development right to erect a new agricultural building at all, so the part 6 prior notification or planning permission choice does not exist and a full application is the only route.

Get the unit area right before anything else, because it is measured as the agricultural unit rather than the field in which the building will stand.

What Part 6 permits on a holding of five hectares or more

Class A of Part 6 permits the carrying out on agricultural land comprised in an agricultural unit of five hectares or more of works for the erection, extension or alteration of a building, or any excavation or engineering operations, that are reasonably necessary for the purposes of agriculture within that unit.

Three words carry the weight. Reasonably necessary, which is a functional test. Agriculture, which has a statutory definition that includes horticulture, fruit growing, seed growing, dairy farming, livestock breeding and keeping, grazing land, market gardens and nursery grounds. And within that unit, which means a building serving a different holding is outside the right.

For units of at least 0.4 hectares but less than five, Class B permits a narrower list. Extension or alteration of an existing agricultural building within limits, hard surfaces, water and waste receptacles, excavations and waste deposits, and the provision or alteration of private ways. No new buildings.

Unit size, floor area and height limits

The limits in Class A are specific and cumulative, and the one that catches most schemes is the 465 m2 ground area figure, which is calculated taking into account other works of a similar description carried out within 90 metres in the preceding two years.

The aggregation rule is the trap. Two 300 m2 buildings put up eighteen months apart within 90 metres of each other exceed the limit between them, and the second one is unlawful however carefully the first was handled. Keep a dated record of every structure erected under Part 6 with its ground area and location.

On designated land, including National Parks and National Landscapes, Part 6 carries additional prior approval requirements, so read the Part as it applies to article 2(3) land rather than assuming the general position.

Where the 400 metre livestock restriction bites

Class A does not permit a building, structure or excavation used or to be used for the accommodation of livestock, or for the storage of slurry or sewage sludge, where any part of it is within 400 metres of the curtilage of a protected building.

A protected building means a permanent building normally occupied by people, with exclusions for buildings within the same agricultural unit and for dwellings or buildings on another agricultural unit used in connection with that unit. So a neighbour's house 380 metres away removes the right for a livestock shed, while your own farmhouse at 50 metres does not.

Measure it from the curtilage, not the building, and measure to the nearest part of the proposed structure including any lean-to or feed passage. Where the distance is marginal, a full application is the safer course, because a livestock building put up in breach of the restriction is unauthorised development and the enforcement position is uncomfortable for a working farm.

What prior notification actually asks for

Part 6 attaches a notification condition to the larger categories of works, which the order labels significant development. That category covers the erection of a building, a substantial extension or alteration, the formation or alteration of a private way, the carrying out of an excavation or deposit of waste, and the placing of a tank in the ground for slurry or sewage. Where the works fall inside it, the right is conditional on applying to the local planning authority for a determination as to whether its prior approval is required.

The application has to describe the development, with a plan showing the site, and the authority then has 28 days to tell you whether prior approval is required. If it says no, or says nothing within the period, you may proceed in accordance with the details submitted.

The scope is limited, and this is the part that gets misunderstood. The authority is deciding whether it needs to approve the siting, design and external appearance of the building, or the siting and means of construction of a private way. It is not deciding whether the building is acceptable in principle.

The matters a council may control

If prior approval is required, the authority can then approve or refuse the siting, design and external appearance. That is a real power, because a refusal of those details stops the building until acceptable details are agreed.

What the authority can do with it. Move the building within the site to reduce landscape or neighbour impact. Require a different roof and wall colour, usually a dark recessive finish. Change the ridge height within the 12 metre limit. Require screen planting. Specify the surfacing and alignment of a new private way.

What it cannot do. Refuse on the ground that the farm does not need the building, since that is a question about whether the right exists at all rather than a matter reserved for approval. Impose conditions about use beyond those already in the order. Or require contributions.

Two conditions in the order itself are worth knowing. Development permitted by Class A has to be begun within five years of the date on which the authority was notified. And where an agricultural building erected under the right ceases to be used for agriculture within ten years of substantial completion, and planning permission has not been granted for another use, the building has to be removed and the land restored. The question of what counts as starting work is the same one addressed in a material operation or lawful implementation of a permission.

Why a full application is sometimes the faster route

Four situations where the full route wins.

The authority disputes agricultural necessity. Arguing it through notification wastes months and ends with an enforcement risk, whereas a planning application puts the functional need in a Planning Statement and gets a decision you can appeal.

The building is above 465 m2 or the aggregation rule is already engaged. Splitting a building to fit the limit produces a worse farm layout than applying once for the building you need.

A later non-agricultural use is intended. This is the big one. The permitted development routes for converting agricultural buildings to dwellings or to flexible commercial use depend on the building having been in agricultural use at specified past dates, or for a period of years, so a new building erected under Part 6 cannot be converted under those classes. If a barn is being built with an eye on conversion in a decade, the planning history you create now matters.

Certainty is needed for finance or for a grant. A planning permission is a cleaner document to put in front of a lender than a determination that prior approval was not required.

Reasonably necessary for agriculture, and how it is tested

The test is objective and it looks at the holding. What is farmed, at what scale, what the existing buildings are used for, what the proposed building will house, and why existing capacity is insufficient. A building for machinery on a holding with no machinery, or a grain store on grassland, invites the question.

Prepare the evidence even for a notification. A short statement of the enterprise, the livestock numbers or cropped areas, the existing building schedule with uses, and the functional reason for the new structure. It costs little and it is the document that persuades an officer not to challenge the right.

Where the position is arguable, a certificate of lawfulness of proposed use or development under section 192 of the Town and Country Planning Act 1990 is the formal way to establish that the works would be lawful, and it is the only way to get that confirmation with legal effect.

Choosing between the two

Run four checks. Unit area at five hectares or more. Ground area of the proposed works against 465 m2 including the aggregation. Distances to classified roads and, for livestock, to protected buildings. And whether any non-agricultural use is contemplated within the next decade.

If all four are comfortable, notify. If any is marginal, apply. Design matters either way, and where prior approval is required a short Design and Access Statement with elevations and a colour specification will do more than a lengthy justification. Where the proposal takes agricultural land out of production, the quality of that land becomes relevant, which is the subject of an Agricultural Land Classification survey.

Browse the 66 report types to see which documents a rural scheme needs. This is general guidance, not legal advice, so check the position with your local planning authority or a qualified professional before relying on it, and read the current consolidated version of Part 6 rather than a summary.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.