Quick Answer: The most common steel farm shed sizes in Ireland are 40×30 ft (about 111 sq m), 60×40 ft (223 sq m), 80×40 ft (297 sq m) and 100×50 ft (465 sq m). Smaller sheds suit machinery storage or small livestock groups, while larger spans handle dairy herds, slurry storage and bulk hay. A handy rule of thumb: an 80×40 ft shed (297 sq m) is the largest that still fits under the 300 sq m animal-housing planning exemption, which is why it is one of the most popular farm shed sizes we build. Whatever you choose, size for the operation you will have in five years, not just today.
“What size shed do I need, and what will it cost?” is the question we hear most at Sullivan Steel. The honest answer is that farm shed sizes are not one-size-fits-all, the right dimensions come down to what you are storing or housing, your site, your planning position and your budget.
This guide runs through the most common farm shed sizes in Ireland, what each one actually holds, how the sizes line up with planning exemptions and grants, and roughly what they cost to build in 2026.
Common Farm Shed Sizes in Ireland at a Glance
Here is how the most common steel farm shed sizes compare on floor area, typical use and indicative cost. The cost bands come from our steel shed cost guide, treat them as a starting point, because spec, site and finish move the final figure:
| Size (ft) | Floor area | Typical use | Indicative cost, erected |
|---|---|---|---|
| 40 x 30 | ~1,200 sq ft (111 sq m) | Machinery store, small livestock group, workshop | €8,000–€15,000 |
| 50 x 40 | ~2,000 sq ft (186 sq m) | Mixed livestock, calf housing, medium machinery | €12,000–€25,000 |
| 60 x 40 | ~2,400 sq ft (223 sq m) | Dairy cubicles (around 40 cows), general-purpose | €15,000–€30,000 |
| 80 x 40 | ~3,200 sq ft (297 sq m) | Larger herd housing, hay plus machinery | €25,000–€45,000 |
| 100 x 50 | ~5,000 sq ft (465 sq m) | Large dairy, bulk storage, industrial-scale | €35,000–€65,000+ |
Those figures are indicative and erected, cladded and finished, not a flat-pack kit landed on a truck. For a full breakdown of what pushes the price up or down, see the cost guide.
How Big Should Your Farm Shed Be?
Before you settle on a number, work back from the job. Different uses have completely different sizing logic:
- Livestock sizes around animal numbers and welfare space, roughly 4–6 sq m per dairy cow in cubicles, 8–10 sq m in loose housing.
- Machinery sizes around eaves height and door width for modern kit, 6 m eaves and a 5 m door are safer than most people expect.
- Hay and silage size around annual yield, roughly 1 sq m per round bale stacked three high.
- Slurry sizes around stocking and storage period, about 0.33 cubic metres per dairy cow per week.
We cover the per-use maths in detail in our guide to what size farm shed you need. The short version: pick the use, size that, then add room to grow.
What Each Farm Shed Size Actually Fits
40 x 30 ft (111 sq m)
The workhorse small shed. Comfortably holds two or three tractors with implements, a small calf group, or a workshop and store. Popular as a second shed or on smaller holdings.
50 x 40 ft (186 sq m)
A useful mid-size for mixed use, a calf shed with a machinery bay, or a modest cubicle house. Big enough to be genuinely versatile without tipping into the larger cost bracket.
60 x 40 ft (223 sq m)
One of the most common new-build farm shed sizes in Ireland. Suits around 40 dairy cows in cubicles with a feed passage, or general-purpose livestock and storage. Sits well inside the 300 sq m animal-housing exemption.
80 x 40 ft (297 sq m)
The “as big as I can build without planning” size. At 297 sq m it slips just under the 300 sq m animal-housing exemption, so it is a favourite for farmers who want maximum space with minimum paperwork. Handles a larger herd, or hay and machinery under one roof.
100 x 50 ft (465 sq m)
Serious scale, large dairy operations, bulk fodder storage, or industrial-style buildings. Above the animal-housing exemption, so it will usually need planning permission, but the cost per square metre is keen at this size.
Farm Shed Sizes and Planning Permission
Size and planning are joined at the hip in Ireland. Under the December 2025 exemptions, you can usually build up to 300 sq m of animal housing per building (450 sq m cumulative across the holding over four years) and up to 900 sq m for other agricultural use without planning permission, provided you meet the setback and siting conditions.
That 300 sq m line is why an 80 x 40 ft shed (297 sq m) is so popular: it is the largest standard size that stays exempt for animal housing. Go to 305 sq m and you are into full planning. For the full rules and conditions, read our guide to the 2026 planning exemptions.
Farm Shed Sizes, Cost and Grants
Bigger is more expensive in total, but the cost per square metre usually falls as the shed grows, the fixed costs of mobilising, foundations and finishing spread across more floor area. Span matters too: a wide clear-span shed needs heavier steel, so a 40-ft-wide building costs disproportionately more per square metre than a narrower one.
If you are a working farmer, a TAMS 3 grant can cover 40–60% of the build up to a €90,000 investment ceiling, so it is worth sizing your project to make the most of that ceiling. For the full price picture, see our steel shed cost guide.
Getting Farm Shed Sizes Right
After years of building farm sheds across the South East, the single most common regret we hear is not overspending, it is building too small. Five years on, the herd has grown, the machinery is bigger, or the planning rules have moved, and the shed that fit perfectly now feels tight.
A shed built 20% bigger than the space you need today is almost always cheaper than the extension you will eventually want. And if your requirements fall outside standard farm shed sizes, an unusual span, integrated tanks, or a specialist layout, that is where bespoke steel fabrication comes in. Teagasc also publishes useful farm buildings guidance worth a look before you commit.
Frequently Asked Questions
Q: What is the most common farm shed size in Ireland?
The 60 x 40 ft shed (around 223 sq m) is one of the most common new builds, it suits a medium dairy or beef operation and sits comfortably inside the 300 sq m animal-housing planning exemption.
Q: How big is a 60 x 40 ft shed in square metres?
A 60 x 40 ft shed is about 2,400 sq ft, which is roughly 223 sq m of floor area.
Q: What is the biggest farm shed I can build without planning permission?
For animal housing, up to 300 sq m per building is usually exempt. An 80 x 40 ft shed (297 sq m) is the largest standard size that stays under that limit, anything bigger generally needs planning permission.
Q: Do you build an 80 x 40 ft steel farm shed?
Yes. The 80 x 40 ft size is one of the most popular we build, precisely because it is the largest that stays under the animal-housing exemption. We fabricate and erect it to your spec across Wexford and the wider South East.
Q: How much does a farm shed cost by size in Ireland?
Indicatively, a 40 x 30 ft shed runs €8,000–€15,000, a 60 x 40 ft €15,000–€30,000, and a 100 x 50 ft €35,000–€65,000+ erected. Spec, site and finish move the figure, see our cost guide for the detail.
The Bottom Line
Farm shed sizes in Ireland run from a 40 x 30 ft workhorse to a 100 x 50 ft industrial-scale building, and the right one comes down to what you are housing, your planning position and your budget. If there is one thing to take away: build for the operation you will have in five years, and where you can, size to make the most of the 300 sq m exemption and your TAMS ceiling.
If you want to talk through the right size for your farm and get an honest, no-obligation quote, get in touch with Sullivan Steel. We will walk the site with you, work back from what you actually need, and give you a clear price with realistic timelines.
