Which reports a new livestock building needs

A new livestock building on an established farm may need nothing more than a prior notification. Or it may need a full application with ammonia modelling, an odour assessment and a landscape study. The difference usually comes down to three things: how big the unit is, how close the nearest house is, and what designated habitat lies downwind.

Work those out before you commission anything, because the answers decide whether you are in the permitted development route at all.

Agricultural prior notification and where it stops

Part 6 of Schedule 2 to the General Permitted Development Order 2015 gives agricultural units of five hectares or more rights to erect certain buildings, subject to prior notification to the local planning authority. The authority then has 28 days to decide whether its prior approval is required for the siting, design and external appearance.

The limits matter more than the right. The ground area covered must not exceed 1,000 square metres, the building must not exceed 12 metres in height, and it must not be within 25 metres of the metalled surface of a trunk or classified road. Smaller units between 0.4 and five hectares have a more restricted right under a separate class.

Then there is the restriction that stops most livestock schemes. A building designed for accommodating livestock, or a structure for storing slurry or sewage sludge, is excluded from the right where it would be within 400 metres of the curtilage of a protected building, which broadly means a dwelling or other building in residential or institutional use, other than one on the same agricultural unit.

That 400 metre rule catches a great many farm layouts. Measure it before anything else. If you are inside it, you are making a full planning application and the document set changes completely.

Odour and its effect on nearby homes

Odour from livestock housing comes from the animals, from the bedding and from the muck store, and it is highly variable with wind, temperature and management.

There is no statutory separation distance in England. Assessment follows the odour guidance published by the air quality institute, using either a qualitative source-pathway-receptor approach for smaller schemes or dispersion modelling where the scale or the proximity warrants it.

An Odour Assessment should identify the sources, the release characteristics of each, the receptors and their sensitivity, the prevailing wind, and the management measures proposed. Ventilation design is the main control: ridge outlets with sufficient discharge velocity carry further before dispersing than low-level side vents, and the choice is a planning matter as well as a welfare one.

Muck and slurry handling is what generates complaints in practice. Cover the timing of spreading, the storage arrangements and the routes used, and say so in the application rather than leaving it to be conditioned.

Ammonia deposition on designated habitats

This is the issue that stops livestock applications, and it is technical.

Intensive livestock housing emits ammonia, which deposits on vegetation downwind and damages sensitive habitats. Natural England will be consulted where a designated site lies within the relevant screening distance, and its response is usually decisive.

The assessment compares predicted concentrations and deposition rates against published critical levels and critical loads for the habitat in question, using dispersion modelling with the emission rate derived from the number and type of animals, the housing type and the ventilation arrangement. Where the process contribution is above the screening threshold, the modelling has to be refined and combined with existing background levels.

Check the Impact Risk Zones for Sites of Special Scientific Interest at the outset, which our note on sites inside an SSSI Impact Risk Zone explains. Ancient woodland, lowland heath and raised bog are the habitats most sensitive to nitrogen deposition, and a site within a few hundred metres of any of them needs the modelling done before the design is fixed.

An Air Quality Assessment covering ammonia is a specialist exercise, and councils expect an author with the relevant competence.

Permitting and environmental impact assessment

Two separate regimes sit alongside planning and have their own thresholds.

Intensive pig and poultry installations above the thresholds in the Environmental Permitting Regulations 2016 require a permit from the Environment Agency, which brings its own assessment of emissions and best available techniques. The permit is not a substitute for planning permission and the two run in parallel.

Environmental impact assessment can be triggered in two ways. Installations for the intensive rearing of poultry or pigs above the Schedule 1 thresholds require assessment automatically. Below those, intensive livestock installations sit in Schedule 2, where new floorspace above 500 square metres brings the proposal into screening territory and the authority decides whether significant effects are likely.

Request a screening opinion rather than guessing. It costs nothing and it settles the question in writing.

Slurry, manure and clean water separation

Storage capacity is regulated separately from planning through the silage, slurry and fuel oil regulations and the rules protecting water, with additional requirements in nitrate vulnerable zones. Planning cares about where the store sits, how it looks, how it is accessed and what happens to the water around it.

Separate clean water from dirty water at the design stage. Roof water goes to a clean system and away, yard water and anything contaminated goes to the dirty water store, and the two must not be able to cross-connect. A drainage plan showing the two systems in different colours answers the question before the environmental health officer asks it.

Size the store honestly against the regulations and the herd, and show the calculation. Understating capacity to reduce the visual impact of a tank is a false economy, because you will be back for a further application within two years.

Access, vehicle movements and the road

Livestock buildings generate feed deliveries, muck movements, milk collection or bird catching, and periodic vehicle peaks that the ordinary farm access was not designed for.

Deal with the visibility splay at the junction, the standing area inside the gate so vehicles are off the carriageway, and the surface for the first 20 metres. Depositing mud on the highway is an offence under the Highways Act 1980, and a condition requiring wheel washing on a farm access is unworkable, so the answer is a hard surfaced apron and a road sweeping arrangement.

State the vehicle types and the movements per week honestly. Highway officers are more sceptical of a claim of no change than of a stated increase.

Landscape treatment and building design

Large span agricultural buildings are hard to hide and easy to site badly. The arguments that succeed are about grouping, colour and topography.

Site the building against an existing group of farm buildings rather than in isolation. Set the ridge below the skyline where the ground allows it. Use dark recessive colours for the roof and upper walls, with a specification rather than a description. Plant with native species in a structure that reflects the local field pattern, and commit to management for at least five years.

Where the site sits in a National Landscape, a National Park or a sensitive valley, a Landscape and Visual Impact Assessment following the third edition of the published guidelines is the expectation, with viewpoints agreed with the authority before the photography is done.

This is general guidance, not legal advice. Check the position with your local planning authority, the Environment Agency and a qualified professional before relying on it. For specialist technical reports, qualified professional input may be required.

Browse all 66 PlanScope report types to see which documents your scheme is likely to need.

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