Permission for a poultry unit and its EIA screening
Bird numbers and new floorspace decide whether a poultry unit needs an environmental statement, and ammonia deposition on nearby habitats usually decides the application.
Poultry unit planning permission turns on two numbers before it turns on anything else: the number of bird places and the area of new floorspace. Above 85,000 broiler places or 60,000 hen places the scheme is Schedule 1 development under the Town and Country Planning (Environmental Impact Assessment) Regulations 2017 and an environmental statement is mandatory. Below that, a new intensive livestock building with more than 500 m² of new floorspace is Schedule 2 development and the authority has to decide whether the effects are likely to be substantial enough to require assessment.
Most farm-scale proposals land in the second category, which is where the arguing happens.
Which thresholds put a unit into EIA territory
Schedule 1 of the 2017 Regulations lists installations for the intensive rearing of poultry or pigs above stated capacities. Reach one and there is no discretion: an environmental statement is required, prepared by competent experts as the Regulations demand. An Environmental Impact Assessment at that scale is not a document an applicant assembles alone, and any AI-assisted draft is a starting point for the coordinating consultant rather than a substitute for one.
Schedule 2 works differently. Intensive livestock installations appear at paragraph 1(c) with an applicable threshold of 500 m² of new floorspace. Passing the threshold does not mean EIA is needed. It means the council must screen the proposal against the selection criteria in Schedule 3, looking at the characteristics of the development, its location and the type and characteristics of the potential impact.
| Route | What triggers it | What follows |
|---|---|---|
| Schedule 1 | Capacity above the listed bird or pig numbers | Environmental statement required, no screening discretion |
| Schedule 2 | New floorspace above 500 m² for an intensive livestock installation | Screening opinion, then EIA only if likely effects are substantial |
| Below thresholds | Small extensions and replacement buildings | Ordinary application, though effects still assessed on their merits |
A sensitive location can pull a modest building into EIA even where a larger one in open arable country would escape it. Proximity to a European site, a site of special scientific interest or a densely settled village changes the answer.
Ammonia deposition and protected habitats
Ammonia is the issue that decides most poultry applications in England, and it is the one applicants underestimate. Housed birds emit ammonia continuously, it disperses, and it deposits as nitrogen on vegetation downwind. Sensitive habitats respond badly.
The screening practice that has developed around environmental permits is also what planning officers and Natural England expect to see. Detailed dispersion modelling is normally triggered where designated habitats lie within a defined screening distance of the installation, and the results are compared with critical levels for ammonia in air and critical loads for nitrogen deposition on the particular habitat. A process contribution below a small percentage of the relevant critical level or load is generally treated as insignificant, and above it the assessment has to go further.
Two points practitioners get wrong. The first is in-combination effects: existing units nearby count, and a cluster of farms can exhaust the headroom before your building is even considered. The second is that a European site brings the Conservation of Habitats and Species Regulations 2017 into play, so the council must screen for likely significant effect and may need an appropriate assessment with Natural England's input. Verify the current screening distances and critical loads at write time, because the guidance is revised.
Mitigation that carries weight includes reduced-emission housing and ventilation design, manure removal frequency, tree planting to intercept the plume, and in some cases scrubbers. Landscape planting works slowly, so claiming full interception from day one does not survive scrutiny.
Odour and separation from dwellings
There is no national separation distance between a poultry unit and a dwelling. Councils and inspectors assess odour on the evidence, which means a dispersion-based or qualitative Odour Assessment prepared to recognised industry guidance, with the frequency, intensity, duration, offensiveness and location of the source all addressed.
The practical drivers are ventilation stack height and direction, prevailing wind, the distance to the nearest sensitive receptor and the management of the litter. Cleaning-out days produce the worst episodes, so a scheme that sets out how and when clearing will happen, and which route the lorries take, answers the complaint before it is made.
Litter, slurry and what happens to it
Councils routinely ask where the manure goes, and an answer of "spread locally" is not one. Storage has to comply with the agricultural pollution regulations covering silage, slurry and fuel oil, and spreading with the rules protecting water. Where litter leaves the holding, the application should state the destination, the vehicle movements involved and the storage arrangements in the interim.
Where litter is burned or digested on site, that is a separate use with its own permitting and its own planning consequences. Treat it as a second proposal rather than a footnote.
Traffic from feed deliveries and catching
Vehicle movements from a poultry unit are few but heavy and concentrated. Feed deliveries arrive in articulated bulk blowers. Catching crews arrive overnight, often between midnight and 4am, with several lorries in convoy. Egg collection is more regular but lighter.
Set that out honestly in the transport section: movements per week by vehicle type, the access geometry, visibility splays at the junction with the public highway, and the condition of the lane. Night-time movements past dwellings on a single-track lane are a common reason for objection and sometimes for refusal.
Scale, landscape and building design
A modern broiler shed is long, low and wide, and there is only so much a landscape officer can do with it. Design work that helps is orientation along the contour rather than across it, dark recessive cladding colours, avoiding ridge-line positions, grouping new buildings with the existing farmstead, and native planting in blocks rather than a thin screen belt.
Where the site lies in or near a National Landscape or a National Park, a Landscape and Visual Impact Assessment prepared to GLVIA3 is effectively obligatory, and the statutory duty on the decision maker raises the bar. Elsewhere a proportionate landscape appraisal with photomontages from public vantage points is usually enough.
The environmental permit running alongside
Intensive poultry farming above the capacity set in the Environmental Permitting (England and Wales) Regulations 2016 needs a permit from the Environment Agency as well as planning permission. The two regimes run in parallel and neither waits for the other.
That overlap is useful. A planning authority is entitled to assume that matters controlled under the permitting regime will be controlled effectively, which keeps duplicate conditions off the decision notice. It also means the ammonia modelling prepared for the permit can serve the planning application, provided the scenarios match.
What a screening request should contain
A screening request under the 2017 Regulations is short, and a good one saves months. Include the following.
- A plan showing the site, the holding and all designated sites within the relevant screening distances.
- A description of the development with bird numbers, building footprint in m² and ventilation arrangements.
- Existing and cumulative livestock capacity on the holding and at nearby units.
- An ammonia screening output, even a preliminary one, with the critical levels and loads used.
- A short assessment against each Schedule 3 criterion, rather than a general assertion that effects are not likely to be substantial.
- Any mitigation already designed in, clearly marked as embedded rather than proposed.
The authority normally has three weeks to adopt a screening opinion, extendable by agreement. A Planning Statement that carries the same evidence through into the full application keeps the argument consistent between the two stages.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. Environmental statements must be prepared by competent experts under the 2017 Regulations, and PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Enter your postcode on PlanScope to see which reports an intensive livestock proposal is likely to need.
Frequently asked questions
When does a poultry unit need an environmental impact assessment?
Automatically where capacity exceeds the intensive rearing thresholds in Schedule 1 of the EIA Regulations 2017. Below that, a new intensive livestock building with over 500 m² of new floorspace is Schedule 2 development, so the council screens it against the Schedule 3 criteria and requires assessment only where likely effects are substantial.
How close can a poultry unit be to a house?
No national separation distance applies. The question is answered by odour assessment evidence covering source strength, ventilation design, prevailing wind and the sensitivity of the receptor. Councils weigh that alongside noise and traffic. A short distance can be acceptable with good design, and a long one can still fail on a poorly sited stack.
Do I need an environmental permit as well as planning permission?
Yes, above the capacity set in the Environmental Permitting Regulations 2016 for intensive poultry farming. The permit is issued by the Environment Agency and covers emissions and site management. It runs in parallel with the planning application, and the ammonia modelling prepared for one can usually support the other.
What ammonia evidence will Natural England expect?
Dispersion modelling of ammonia concentrations and nitrogen deposition at designated habitats within the screening distances, compared against the critical levels and critical loads for those habitats, with in-combination effects from other livestock units included. Where a European site is affected, the Habitats Regulations screening and any appropriate assessment follow.
Can landscape planting deal with the visual impact?
Only partly, and slowly. A modern broiler shed is large and low, so siting, orientation and cladding colour do more work than screening. Planting takes years to reach effective height, and assessments that claim full screening from the first season are routinely discounted by inspectors.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.