Livestock buildings
A clear span frame designed around air and muck rather than around storage. Tell us roughly what you need and you get engineered drawings and a price — plus honest figures for the floor, the falls and the drainage that the frame quote leaves to you.
- Common span
- 12–24 m
- Set by the pen layout and the feed passage, not by a round number.
- Typical slab
- 175 mm
- Falls and drainage matter more here than raw thickness.
- Sub-base
- 150 mm
- Compacted Type 1, spread around 190 mm loose.
- Planning trap
- 400 m
- No permitted development for livestock housing within 400 m of a protected building.
What you are actually buying
A clear-span frame designed around air and muck rather than around storage. The frame itself is the straightforward part; what makes a livestock building work is where the air comes in, where the effluent goes, and whether the layout lets one person feed and scrape without fighting it.
Span follows the layout
Work back from the pens, the feed passage and the scrape route rather than picking a round number. A span that leaves you a passage half a metre too narrow is a nuisance every day for thirty years.
Length is stock numbers
Bays at 6 metre centres divide up naturally into pens and feed barriers. Build in the spare bay now if there is any chance of it — extending later means groundworks, steel and a planning position all over again.
Height is ventilation
Eaves and ridge together drive the stack effect that pulls stale air out. Too low and it sits; too enclosed and it condenses. Height also has to clear the loader when the shed is being mucked out.
What you get asked to decide
- Space boarding, Yorkshire boarding or sheeted sides, and an open or capped ridge
- Feed barriers, gates and pen divisions, and which end the feed passage runs
- Channels, drains and where dirty water is going before you dig anything
- Cladding down to a concrete panel wall, so the sheeting is not what a bullock leans on
- Supplied for your own team to erect, or supplied and erected
There is one more choice underneath all of those: whether the frame is cold rolled or hot rolled. It changes the price, the lead time, whether you can put it up yourself, and what goes in the ground.
How it goes from here
Five steps, in this order. The fourth is the one nobody prices for you up front, which is why there is a calculator further down this page. The full steel building groundworks calculator for Cornwall and Devon explains every figure it gives you.
Step 1
Tell us roughly what you need
Span, length and what it is for. Approximate is fine — nobody expects you to have decided, and it means the first reply can be useful rather than a list of questions.
Step 2
Drawings and a price for the frame
The manufacturer prepares engineered drawings and quotes the building. That includes the pad foundation sizes, which no calculator can work out for you.
Step 3
Settle the planning position
Prior approval on a qualifying agricultural holding, or a full application. Worth establishing before steel is ordered rather than after.
Step 4
Get the base in
Site strip, level, stone and slab, ready and cured before the erectors arrive. This is the part you can price on this page today.
Step 5
Delivery and erection
Delivered for your own team to put up, or supplied and erected. Both are normal; the difference is worth asking about at quote stage, not later.
Rough dimensions are enough to start. You get a reply the same day.
The floor has to fall somewhere
A machinery store floor can be flat and nobody minds. A livestock floor cannot. Slurry, washings and whatever comes off the stock have to move to a channel, and from the channel to a store — and every part of that route is concrete you are paying for and quantities you need to order.
That changes the shape of the job rather than the thickness of the slab. 175mm with mesh is a reasonable starting point for the housed area, and it is thinner than a machinery store because cattle are a distributed load rather than a turning trailer. What you spend instead goes into falls, channels, kerbs and the collection end.
Concrete has to survive what it stands in
Silage effluent and slurry are acidic. Ordinary concrete does not simply get dirty in a livestock building — it is chemically attacked, and a floor that was specified as though it were a garage will surface-fret and expose aggregate far sooner than the owner expected.
This is a specification conversation to have with your ready-mix supplier rather than a number to read off a web page. Ask for a mix suitable for agricultural effluent exposure and say what it will be holding. Most of the major suppliers have a farm range built for exactly this, and the cost difference at the point of ordering is far smaller than the cost of relaying a floor.
Keep the clean water out of the dirty water
Rain off the roof is clean. It can go to a soakaway or a watercourse and cost you nothing. The moment it mixes with anything off the yard or the floor, it is dirty water — and dirty water has to be contained, stored and spread under the rules.
A roof, not a tank
A 12 × 24 m roof sheds a serious volume of clean water every year. Route it separately at the design stage and it costs you a downpipe. Let it into the dirty system and you are storing and spreading it for the life of the building.
Guttering, downpipes, separate drainage runs and the falls that keep the two apart are groundworks, and they are not in the frame quote either.
The slurry rules, plainly
In England the governing legislation is the Water Resources (Control of Pollution) (Silage, Slurry and Agricultural Fuel Oil) (England) Regulations 2010 — SI 2010/639, known to everyone as the SSAFO Regulations. They came into force on 6 April 2010 and replaced the 1991 regulations in England.
They set construction standards in three parts:
- Silos. The base must extend beyond the silo, base and walls must be impermeable, effluent collection channels are required, and there is a minimum effluent tank capacity.
- Slurry storage systems. Impermeable base and walls, with effluent tanks, channels and pipes to defined standards.
- Farm fuel oil. The storage area must be surrounded by a bund capable of containing the tank contents, with an impermeable bund and base.
There is a notification duty that catches people out: you must tell the Environment Agency at least 14 days before you construct or substantially alter a store, or before you first use a new field silage site. That is a letter, not a licence application — but it is not optional.
A summary, not legal advice, and England only — Wales, Scotland and Northern Ireland have their own instruments. Read SI 2010/639 on legislation.gov.uk and the Environment Agency guidance before you build. Storage capacity requirements differ inside a Nitrate Vulnerable Zone, so check whether you are in one.
The 400 metre rule
Livestock accommodation is the one agricultural building type with an extra planning exclusion. Permitted development rights under Part 6 are removed altogether where the building is for housing livestock and sits within 400 metres of a protected building.
In practice a protected building is a dwelling or similar in separate occupation, so a neighbour's house inside that radius takes the prior approval route off the table and leaves you needing full planning permission. It is the first thing to check on a site, because it changes the timescale and the cost of the whole project rather than a detail of it.
Part 6 of the General Permitted Development Order splits at five hectares, and the two halves are not the same right with different numbers on them.
On a unit of five hectares or more, Class A permits the erection, extension or alteration of a building that is reasonably necessary for agriculture on that unit. The ground area of the building cannot exceed 1,500 square metres. That figure rose on 21 May 2024 — it was 1,000 square metres before then and 465 square metres before April 2018, so an older guide will understate it. A separate cap of 1,000 square metres applies to structures for accommodating livestock and to plant arising from engineering operations.
On a unit of at least 0.4 but under five hectares, Class B does not let you put up a new building at all. This is the part most often got wrong. Class B permits the extension or alteration of an agricultural building you already have — along with plant and machinery, private ways, hard surfaces and services — but there is no erection right anywhere in it. The extension is capped at 1,250 square metres of ground area and at a 25 per cent increase in the original building's cubic content, with no increase in height. If you have four hectares and no building to extend, a new shed is a full planning application.
Where Class A or B does apply, you are not applying for planning permission. You apply to the local planning authority for a determination as to whether prior approval is required for the siting, design and external appearance — currently £249 — and they have 28 days. If they do not respond inside 28 days you may proceed, provided the work genuinely is permitted development in the first place.
The exclusions are where holdings come unstuck, and the 400 metre rule above is the one that bites hardest on livestock. Since 21 May 2024 nothing can be built under Class A or B on land that is, or is within the curtilage of, a scheduled monument.
On protected land the rights are not usually removed, which is a common misunderstanding. What changes inside a National Park is that the prior approval procedure applies more widely — to every extension or alteration rather than only to significant ones. In Cornwall and Devon that means Dartmoor and Exmoor. Cornwall's National Landscape is a different designation and does not take Class A or B away, though an Article 4 direction or a condition on an earlier permission can, and both are worth checking on your own holding.
A summary, not planning advice, and England only. The legislation is Part 6 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015, as amended — most recently on 21 May 2024. Figures checked against legislation.gov.uk in September 2026. Confirm your own position with the authority that covers your site.
What this calculator does not cover
It works out the slab, the sub-base and the earthworks. It does not size your channels, your effluent tank or your slurry store, and it does not size the pad foundations — those come off a structural engineer's design against your span, eaves height, wind loading and ground conditions, and they come with your drawings when you get a price.
For a livestock building, treat the figures below as the floor and the ground it sits on, and price the drainage and containment separately.
Work out the base for your livestock building
Set to a livestock specification. Change the span and length to your building, and tell it what the ground is doing. A 12 by 24 at 175mm comes out around 54.5 cubic metres of concrete for the slab alone, before channels, kerbs and aprons.
What this does not work out: the pad foundations
The concrete pads the stanchions sit on are sized by a structural engineer, not by a formula. They change with the span, the eaves height, the wind loading on your particular site and what the ground will bear. Anyone quoting you a pad size without a design has guessed it.
Want this priced properly?
Send us the job and we'll get you engineered drawings and a quote for the frame — with the pad sizes this tool can't work out. The figures above go with your enquiry, so you don't have to type them again.
Every enquiry gets a reply the same day, and your figures go with it. The building itself is designed and priced by South West Steel Buildings, our building partner, so your details go to them too, and they will be in touch. How we handle your details.
Common questions
- What span should a livestock building be?
- Work backwards from the layout rather than starting with a round number. Set out the pens, the feed passage and the route you will scrape along, add the width you need to get past with a loader, and the span falls out of that. A span that leaves a passage half a metre too narrow is a nuisance every single day for the next thirty years, and it cannot be widened once the frame is up.
- How does a livestock building ventilate?
- Mostly by itself, if it is designed to. Fresh air comes in low through the sides — space boarding, Yorkshire boarding or an open eaves gap — and stale, warm, moist air rises and leaves through an open or capped ridge. That stack effect needs both an inlet and an outlet to work, which is why an enclosed building with sheeted sides and a closed ridge ends up damp and why stock in it get more respiratory trouble. How much opening you need depends on stock numbers, building width and how exposed the site is, so it is worth designing rather than guessing.
- What is different about a livestock building floor?
- Two things. It has to fall to somewhere — channels, a collection point, a tank — because slurry and washings have to leave the building rather than sit in it. And the concrete has to survive what it is standing in. Silage effluent and slurry are acidic, and they attack ordinary concrete over time, so durability against acid attack matters more than adding thickness.
- Do I need permitted development or full planning for a cattle shed?
- Livestock buildings carry an extra exclusion that no other agricultural building has. Permitted development under Part 6 is removed entirely for the accommodation of livestock, and for storing slurry or sewage sludge, within 400 metres of the curtilage of a protected building — broadly a dwelling that is not on your own agricultural unit. Inside that radius you need full planning permission however well the rest of the tests are satisfied. Outside it, the ordinary Class A and Class B rules decide the route, and those differ sharply depending on the size of the holding.
- What are the rules on slurry storage?
- In England, the Water Resources (Control of Pollution) (Silage, Slurry and Agricultural Fuel Oil) (England) Regulations 2010, usually called the SSAFO Regulations, which came into force on 6 April 2010. They set construction standards for silos, slurry storage systems and farm fuel oil storage — impermeable bases and walls, effluent collection channels, minimum effluent tank capacities, and bunding around fuel tanks. You must notify the Environment Agency at least 14 days before building or substantially altering a store, or before first using a new field silage site.
- Does clean roof water have to be kept separate from dirty water?
- Yes, and it is worth designing in from the start rather than retrofitting. Rainwater off a roof is clean and can go to a soakaway or watercourse. Anything that has touched the yard, the floor or the stock is dirty water and has to be contained and dealt with as such. Mixing the two turns a small volume of dirty water into a very large one, and the storage you then need is expensive.
- Do I need planning permission for a farm building?
- It depends on the size of the holding, and the answer is not the same for both classes. On an agricultural unit of five hectares or more, Class A of Part 6 of the GPDO permits the erection, extension or alteration of a building reasonably necessary for agriculture on that unit, up to a ground area of 1,500 square metres — raised from 1,000 on 21 May 2024, and 465 before April 2018. On a unit of at least 0.4 but under five hectares, Class B does not permit a new building at all. It allows only the extension or alteration of a building you already have, capped at 1,250 square metres and at a 25 per cent increase in the original cubic content with no increase in height. A new building on a holding that size needs full planning permission. Where Class A or B does apply you make a prior approval application to the local planning authority, currently £249, and they have 28 days to tell you whether prior approval is required.
- Will putting this building up affect a barn conversion later?
- It can, and it is worth knowing before you commit. Erecting or extending an agricultural building under Class A or Class B blocks a Class Q conversion of a building on that established agricultural unit for ten years, and the reverse also applies — if a Class Q conversion has been carried out on the unit in the previous ten years, you cannot use Class A or B to put up or extend an agricultural building. If a barn conversion is anywhere in your thinking, sequence the two rather than discovering the conflict afterwards.
Other buildings we cover
Same approach on each: what the building is, how it gets sized, where you stand on planning, and what the base underneath it comes to.
Machinery stores
Clear span, no posts in the way, and a floor that works harder than most. What it costs to put up and what it costs underneath.
Grain stores
Walls that get pushed from the inside, a floor that takes a loader, and a roof that rains on the crop if you get it wrong.
Farm workshops
Room to get a machine in and work all round it, with a floor specced for the jack rather than the tractor.
Hay barns
Open sides, air through it, and the lightest slab on the farm — if it needs one at all.
General purpose buildings
The shed that ends up doing everything. How to spec a building for a use you have not decided yet.
Stables and arenas
Stable blocks, American barns and indoor arenas. The same steel frame as a farm building — and a completely different planning position.
Garages and workshops
Steel framed garages, home workshops and man caves at the house. The eaves limit that decides whether you need planning permission, and the floor underneath.
Industrial units
Workshops, warehousing, trade counters and light manufacturing. Full planning, full Building Regs, and a yard that often costs more than the shed.
Get a price for your livestock building
Rough span and length is enough to start with, along with what is going in it. You get engineered drawings and a price for the building, including the pad foundation sizes — and you already know what the floor under it comes to.