Documents for an agricultural building over the Part 6 limits

Once an agricultural building exceeds the limits in Part 6 of the General Permitted Development Order 2015, the prior notification route closes and you are making a full planning application. That is a different exercise in kind, not just in paperwork, because the council can then refuse on landscape, amenity, highways, drainage and ecology rather than only on siting, design and external appearance.

Most farm clients arrive expecting the same 28-day process with a longer form. Setting that expectation straight at the first meeting saves a lot of frustration later.

The size and siting limits in Part 6

Class A of Part 6 applies to agricultural units of five hectares or more and permits buildings reasonably necessary for agriculture, subject to limits that are easy to trip.

Ground area is capped, and the cap counts other agricultural buildings put up nearby within the preceding two years, so a third shed in a group can fail even though each one was within the limit on its own. Height is capped, with a lower limit close to an aerodrome. Nothing is permitted within 25 metres of the metalled part of a trunk or classified road. And livestock housing or slurry storage is excluded within 400 metres of a protected building.

Smaller units between 0.4 and five hectares fall under a different class that permits extensions and alterations rather than new buildings. That distinction catches smallholders regularly.

When prior notification is enough

Where the works are within the limits, you submit a prior notification and the authority has 28 days to decide whether its prior approval is required for siting, design and external appearance.

That is a narrow test, and it has a useful consequence. The authority cannot refuse because it dislikes the agricultural justification or because a neighbour objects to traffic. It can require the building to be moved within the field, or the cladding colour changed, and in designated landscapes it will.

Two conditions travel with the permission. The building must be used for agriculture, and if the agricultural use ceases within ten years of substantial completion without planning permission for another use, the building has to be removed and the land restored. Anyone putting up a shed with a diversification plan in mind should understand that before the slab is poured.

A further point that matters commercially. The biodiversity gain condition attaches to planning permissions granted on application, and development carried out under the permitted development order is treated differently. Check the current exemptions before assuming either way, because that single difference can change the cost of a scheme.

What a full application then requires

Above the limits, the documents follow the ordinary pattern for a rural application, scaled to the site.

• A planning statement setting out the agricultural justification and the policy case.
• A site plan, elevations and sections at proper scales, with a location plan showing the whole holding.
• Ecological information where existing buildings, hedgerows or trees are affected.
• Drainage details covering roof water, yard water and any slurry or silage storage.
• Access and visibility information where farm traffic uses a public road.
• Flood risk information where the site falls in Flood Zone 2 or 3 or exceeds one hectare.

A planning statement does most of the work here. Unlike the prior notification, this application is decided against the development plan, so the statement needs to identify the relevant countryside, landscape and agricultural policies and answer each in turn.

Agricultural need and the unit that supports it

Councils test whether the building is reasonably necessary for the agricultural operation, and they test it with more scepticism the larger the building is.

Set out the holding. Area in hectares, tenure, cropping or stocking, existing building schedule with sizes and current uses, and the operational reason the new building is required. A grain store sized to the harvest from a stated acreage is an argument. A general reference to expanding the business is not.

Where the building is unusually large or the holding is small, expect the officer to ask whether the building serves this unit or a wider contracting operation. Answer that directly. A building serving contract work off the holding may be an industrial use rather than an agricultural one, and the description of development should reflect what will actually happen inside it.

Landscape and design in open countryside

Farm buildings are big, and in open countryside the planning judgement is about siting, massing and colour rather than architecture.

Site the building against existing built form or landform where possible, and show why any more prominent position was chosen. Use a roof pitch that matches the existing group. Specify dark recessive colours for cladding and roof, with a reference to the colour standard rather than a trade name.

Where the site sits in or near a National Landscape, a National Park or a locally valued landscape, a landscape and visual impact assessment prepared to the recognised guidelines with agreed viewpoints is usually proportionate. On a less sensitive site, a landscape appraisal with photographs and a planting plan will often do.

Show planting at a realistic establishment period. A hedge drawn at mature height on a computer visualisation invites the officer to discount the whole document.

Drainage, slurry and manure

Clean and dirty water separation is the principle, and it is a regulatory requirement as well as a planning one.

Roof water should be collected and discharged to a soakaway or watercourse. Yard water that has been in contact with livestock or manure is dirty water and needs containment and storage. Silage and slurry storage is controlled by its own regulations covering construction standards, capacity and separation from watercourses, and the planning drawings should be consistent with what those regulations require rather than showing something that will have to be rebuilt.

Where existing buildings are being replaced or altered, a preliminary ecological appraisal should be commissioned early. Barn owls and bats use agricultural buildings routinely, and survey seasons will not bend to a harvest deadline. The same sequencing applies on livestock schemes generally, as set out in the note on reports needed for an intensive poultry unit.

Access and farm traffic

The highway authority will ask about the access, and the honest answer is often that it has been used for decades without being measured.

Provide a visibility splay drawing against the measured speed of traffic, a swept path for the largest vehicle using the access, and a note on the frequency and seasonality of movements. Harvest peaks matter more than annual averages on a farm.

Where the splay falls short of the standard, say so and set out the case, including any accident record and any physical improvement that is deliverable within land you control. Officers deal with sub-standard rural accesses constantly and they respond better to a measured case than to silence.

Where the building will draw articulated deliveries that the lane has not carried before, describe the route and the passing places. A short routing note agreed with the highway officer before submission often removes an objection that would otherwise take six weeks to resolve.

This is general guidance, not legal advice. Permitted development limits, conditions and biodiversity requirements change, so check the current 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.