Agricultural building prior notification under Part 6

Agricultural permitted development lets you put up a farm building without a full planning application, but only on a holding of five hectares or more, only where the building is reasonably necessary for agriculture, and only after you have gone through prior notification. The class is Part 6 of Schedule 2 to the General Permitted Development Order 2015, and it comes with hard numerical limits on floor area, height and proximity that turn an otherwise permitted building into a breach the moment you cross them.

What Part 6 permits on holdings of five hectares or more

Class A of Part 6 covers works and buildings on an agricultural unit of five hectares or more, where they are reasonably necessary for the purposes of agriculture within that unit. It takes in new buildings, extensions, excavations and engineering operations such as forming a private access track.

The class does not permit dwellings, and it does not permit anything for a non-agricultural purpose. A building for a farm shop, a contracting business, storage for an unrelated enterprise or an equestrian livery is outside the class, however agricultural it looks, and that is the boundary most enforcement cases sit on. Equestrian use in particular is not agriculture in planning terms, as our note on stables, a menage and horses explains.

Class B applies to units between 0.4 and 5 hectares and is much more restricted, mainly allowing extensions or alterations to existing buildings within tight limits rather than new buildings of any size.

The prior notification procedure and the 28 day response

Prior notification is not a permission and it is not a formality. You apply to the local planning authority for a determination as to whether its prior approval is required for the siting, design and external appearance of the building, or for the route and surfacing of a private way.

The sequence matters.

1. Submit the prior notification with a plan showing the site and the proposed building, a description of the proposed development, and the fee.
2. The authority has 28 days to tell you whether prior approval is required.
3. If it says prior approval is not required, you may build in accordance with the details submitted.
4. If it says prior approval is required, you must obtain that approval before starting, and it may attach conditions to siting, design and appearance.
5. If it says nothing within 28 days, you may proceed in accordance with the details submitted.

Do not start on the strength of a phone call. The 28 day period runs from a valid submission, and building before the period expires puts the development outside the class entirely. Fees for prior notification are set nationally and are indexed, so check the current schedule rather than working from an older figure.

Size, height and proximity limits that break the class

These are the numbers that decide whether you can use the class at all.

The 465 m² area limit is cumulative in effect, because the class restricts development where works have already been carried out on the unit within a defined period and distance. Splitting a large shed into two smaller ones on adjacent plots does not reliably get round it, and councils check.

Verify each figure against the current text of Part 6 before you commit, since the Order is amended regularly and a limit quoted in an old article may no longer be the one that applies.

Reasonably necessary for agriculture

This is the test applicants underestimate. It is not enough that the applicant farms. The building itself must be reasonably necessary for the agricultural use of that unit.

Provide the evidence in the notification rather than waiting to be asked: the extent and tenure of the holding with a plan, the enterprise it supports, the existing building stock and why it is inadequate, and what the new building will hold. Where the unit is close to five hectares, prove the area properly, because a shortfall means the class does not apply at all.

Officers see through capacity that exceeds the holding. A grain store sized for three times the arable area on the unit invites the conclusion that the building serves a contracting business or storage let, which is not agriculture.

Slurry, livestock and the 400 metre rule

The 400 m rule is the one that scuppers most livestock proposals. A building or structure for accommodating livestock, or for storing slurry or sewage sludge, cannot be built within 400 m of the curtilage of a protected building under the class.

A protected building means, broadly, a permanent building normally occupied by people, with exclusions including buildings on the same agricultural unit. Measure from the curtilage rather than the wall, and remember that neighbouring farm cottages sold off the holding count.

Where the distance cannot be achieved, the answer is a full planning application, which brings odour, noise and traffic into play. Plan for that from the start: an odour assessment, a manure management plan and a highways note tend to be needed, and the case is easier when the building is grouped with the existing farmstead.

Access tracks and hardstanding under the same class

Private ways serving the agricultural unit are within Class A, and they are subject to prior notification of the route and surfacing. This is worth using properly. A well drawn track application, showing surfacing materials, drainage and where it meets the public highway, usually goes through without difficulty.

Two cautions. Where the track forms a new access onto the public highway, that element needs the highway authority's separate consent and may fall outside the class. And where the route crosses a public right of way or affects a hedgerow, other regimes apply, including the notice requirements for removing an important hedgerow.

When a full application is unavoidable

Reach for a full application where the building exceeds 465 m² or 12 m, where livestock or slurry cannot be kept 400 m from a protected building, where the holding is under five hectares, where the use is not agriculture, or where the site sits in a designated landscape with tighter restrictions on the class.

A full application is slower but it settles the position. It also produces a permission you can show a lender or a buyer, which prior notification does not do in the same way. Set the case out in the Planning Statement, addressing agricultural need, siting, landscape effect and access. Where the building supports a diversification project rather than farming itself, the test shifts to rural economy policy, as covered in our guide to farm shops and the diversification test.

PlanScope drafts the supporting documents around your holding details and flags where evidence is still needed, and the full list of report types shows what a rural application usually requires.

This is general guidance, not legal advice. 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.