10 vs 20 ft · Shelving · Condensation · Cost
Shipping Container Shed
As a shed, the container’s pitch is blunt: more secure than any timber building, watertight from day one, delivered finished in an afternoon. The catch list is equally short: it looks like a container, it needs a ventilation plan, and below 20 ft the economics stop working.
The working dimensions: a 20 ft box is 5.898 × 2.352 × 2.393 m inside (13.9 m², 33.2 m³) behind a 2.340 × 2.280 m door; a 10 ft is 2.831 × 2.352 m (6.6 m², 15.9 m³). General storage sizing across the range is in the storage container guide — this page is specifically about the backyard-shed use case.
10 ft vs 20 ft as a shed
The 20 ft is the default for one economic reason: 10 ft containers are not mass-produced — most are cut down from 20 ft units, and the fabrication makes them cost $1,500–2,500 used against $1,000–2,500 for a full 20 ft. You pay the same money for half the space; a 10 ft earns its place only where the yard physically cannot host 6 m of steel, or where towing it in on a trailer matters (1,300 kg tare — a heavy but feasible trailer load; a 20 ft at 2,230 kg needs a truck).
| Size | Internal floor | Volume | Used price | $/m² |
|---|---|---|---|---|
| 10 ft | 2.83 × 2.35 m = 6.6 m² | 15.9 m³ | $1,500–2,500 | $227–379 |
| 20 ft | 5.90 × 2.35 m = 13.9 m² | 33.2 m³ | $1,000–2,500 | $72–180 |
For garden-tool duty, grade can go low: wind-and-water-tight ($1,000–1,900 for a 20 ft) is precisely the shed spec — dry and lockable, no shipping certification you will never use. What to check before paying is in the buying guide.
Shelving: the aisle math
The 2.352 m internal width supports exactly one rational racking plan: 0.6 m deep shelving down both long walls, leaving a 2.352 − 1.2 = 1.15 m centre aisle — comfortable for a person with a box, workable for a wheelbarrow. Deeper 0.75 m industrial racking on both sides pinches the aisle to 0.85 m (one-side-only is the fix); a 20 ft so fitted carries ~14 linear metres of racking or 28–42 m of shelf at 2–3 levels, plus ceiling headroom for long items on top at 2.39 m.
Two load facts complete the plan. The 28 mm plywood floor takes point loads a wood shed floor never could — engine stands, machine tools, stacked cement — see container flooring for ratings. And the corrugated steel walls take self-drilling screws for hanging rails and brackets directly into the corrugation crests; no studs to find, but seal each penetration against rust.
Condensation: the one problem to engineer away
The container shed’s single failure mode is water from the inside. Steel tracks the night sky: on clear nights the roof cools below the dew point of the humid air inside, and moisture condenses on the ceiling and drips onto whatever is stored — “container rain”. Damp lawnmowers, firewood or cardboard boxes load the air with the very moisture that returns as drips; tools rust, fabrics mildew.
The fix is airflow, and it is cheap: four or more louvred vents ($15–40 each, fitted low on one wall and high on the opposite wall for cross-stack convection), or a wind-driven turbine vent on the roof. Add habits — don’t seal wet equipment in, keep cardboard off the floor on the racking, drop moisture absorbers in for winter — and the problem disappears. The dew-point physics and vent sizing are in the ventilation guide.
Ground prep: the gravel pad
A shed container needs no concrete. The specification: strip vegetation, lay and compact 150–200 mm of crushed gravel extending ~300 mm beyond the container footprint, screed it level — total $300–1,000 for a 20 ft, DIY-able in a weekend. The pad drains rain away from the bottom rails (parking steel on damp soil is how floors rot from below) and spreads the load; on soft ground, add concrete pavers or railway sleepers under the four corner castings, where nearly all of the 2.2–10 t total weight concentrates. Full base options, including when piers are worth it, are in the foundation guide; delivery needs a straight ~18 m tilt-bed approach, per the moving guide.
Is a container cheaper than building a shed?
At 20 ft size, honestly yes. The delivered numbers: used 20 ft container ≈ $1,200–2,500 + $300–1,000 pad + $150–500 delivery = $1,650–4,000 for 13.9 m², i.e. $119–288/m² all-in. A stick-built wood shed of that size runs $150–400/m² in materials alone ($2,100–5,600) before the weekends of labour, and a comparable prefab metal building lands similar with a lighter shell and a mandatory anchoring kit. The container arrives storage-ready the same afternoon, with 1.6–2 mm of steel and a lockable door no wood shed matches.
The honest flip side: at small sizes the container loses — a $1,500–2,500 10 ft is beaten on price by any 6 m² garden shed kit ($500–1,500); a container cannot be sited tight against a fence in pieces (it needs its crane/tilt-bed approach); HOAs and some zoning codes reject the aesthetic outright; and a wood shed can be built to any footprint, while containers come in exactly two. The break-even rule of thumb: need ≥10 m² of secure storage and have delivery access — container; need <8 m² or must match the house — build.
Frequently asked questions
Is a shipping container cheaper than building a shed?
At 20 ft size, yes: $1,650–4,000 all-in (used box + gravel pad + delivery) for 13.9 m² ≈ $119–288/m², versus $150–400/m² in materials alone for a stick-built wood shed — plus the container arrives finished. Below ~8 m² the answer flips: a 10 ft container costs nearly as much as a 20 ft, and small shed kits beat it easily.
How much does a container shed cost?
A used wind-and-water-tight 20 ft runs $1,000–1,900 and a cargo-worthy one $1,200–2,500; add $150–500 delivery and $300–1,000 for a gravel pad. A 10 ft, if you truly need the small footprint, runs $1,500–2,500. Vents add $60–160.
Does a container shed need a foundation?
Not concrete — a 150–200 mm compacted, levelled gravel pad is sufficient and doubles as drainage. On soft ground put pavers or sleepers under the four corner castings, which carry nearly all the weight. What matters is level: a twisted box makes its own doors stiff.
Will my tools rust inside a container?
Only if you seal it. An unvented steel box condenses moisture on cold nights (“container rain”) and drips it back on the contents. Four louvred vents placed low/high on opposite walls, dry goods in, and moisture absorbers over winter keep the interior rust-free.
How long will a container shed last?
25+ years in static duty with minimal care. The Corten shell outlives any timber shed; the wear items are the door gaskets (replaceable) and the paint at dents and cut edges (touch up with zinc primer). Keep the roof draining and the bottom rails off wet soil.
Do I need a permit for a container shed?
Often not, sometimes yes. Many US jurisdictions exempt accessory structures under 100–200 ft² — which covers a 10 ft but not a 20 ft (150 ft²) — and rules diverge sharply on containers specifically; HOAs frequently prohibit them on sight. One phone call to the local building department before ordering settles it.
How much fits in a 20 ft shed container?
33.2 m³ — roughly the contents of a 3-bedroom house, or in shed terms: ride-on mower, two bikes, full racking down both walls (28–42 shelf-metres at 0.6 m depth) and a 1.15 m aisle to walk in. The 2.28 m door height admits anything a garden owns.
Can I put shelves on container walls?
Yes — self-drilling screws or bolts go straight into the corrugation crests, no studs needed; the steel carries rails, brackets and French cleats anywhere along the wall. Seal each penetration with sealant or use rivnuts to keep rust out. Freestanding racking works too and leaves the shell unpierced.