Livestock buildings
The building where the floor is the hardest part of the job. Not because of what stands on it, but because of what runs across it, what it has to drain to, and what the law says has to happen to that once it gets there.
- Typical slab
- 175 mm
- Sub-base
- 150 mm
- Concrete, 12 × 24 m
- 54.5 m³
- Planning trap
- 400 m
Falls and drainage matter more here than raw thickness.
Compacted Type 1, spread around 190 mm loose.
Slab only. Channels, tanks and aprons are extra.
No permitted development for livestock housing within 400 m of a protected building.
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.
Outside that, the ordinary tests apply: Class A on agricultural units of five hectares or more, Class B on units between 0.4 and five hectares, and in both cases the building must be reasonably necessary for agriculture on that unit. Rights are also restricted on protected land, which covers a substantial part of Cornwall.
A summary, not planning advice. The legislation is Part 6 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015, as amended. Talk to Cornwall Council about your own 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.
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.
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 are sent with it. We are not a steel building manufacturer — we pass your details to a steel building supplier so they can price the job and contact you. How we handle your details.
Common questions
- 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 are the one agricultural type with an extra exclusion. Permitted development rights under Part 6 of the GPDO are removed entirely for the accommodation of livestock within 400 metres of a protected building — broadly, a dwelling or similar in separate occupation. Outside that, the usual Class A and Class B tests apply on holdings of five hectares or more, and 0.4 to under five hectares respectively.
- 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.