Enter the footprint, pick how it's built, and get a building cost range — plus the gravel pad volume and weight underneath it.
Quick answer: A 10 × 12 ft (120 sq ft) prefab kit runs 120 × $12–$40 = $1,440–$4,800. The gravel pad at 4 inches adds 120 × 0.333 / 27 = 1.48 yd³ of crushed stone (~2.07 tons), material-only.
Ballpark, not gospel. Building ranges are typical US figures for the structure itself — permits, electrical, grading, and delivery are not included. Get local quotes before you commit.
| Build type | Per sq ft | Best for |
|---|---|---|
| Prefab kit | $12–$40 | Budget storage, fast install |
| Custom-built | $60–$120 | Odd sizes, matching the house |
| Finished shed home | $100–$200 | Office, studio, guest space |
All three sit on the same thing: 4 inches of compacted crushed stone. Size yours with the gravel calculator — our shed base guide covers depth, edging, and drainage.
Straight answers, no fluff. Then run your own numbers above.
At 120 sq ft: a prefab kit runs $1,440–$4,800 ($12–$40 per sq ft), a custom-built shed runs $7,200–$14,400 ($60–$120 per sq ft), and a finished, insulated shed home runs $12,000–$24,000 ($100–$200 per sq ft). Typical US ranges; permits, electrical, and site prep are extra.
The kit — by a wide margin. Prefab kits run about $12–$40 per sq ft versus $60–$120 for a contractor-built custom shed, and kits go up in a day or two. Custom wins when you need an odd size, a specific look, or a structure the kit makers don't sell. Having a pro assemble your kit adds roughly $10–$20 per sq ft.
Footprint × depth ÷ 27. A 10 × 12 ft pad at 4 inches deep: 120 × 0.333 ÷ 27 = 1.48 cubic yards, about 2.07 tons — one small delivery load. The calculator above sizes the pad from your exact footprint.
A gravel pad runs roughly $1–$2 per square foot versus $10–$12 for a concrete slab (typical ranges). Gravel drains better, is far cheaper, and is the standard base under prefab sheds. Concrete wins for heavy workshops and anywhere you want a perfectly flat, permanent floor.
Often, yes. Many cities require a building permit for sheds over 120 sq ft, and almost always for sheds with electrical or plumbing. Permits typically run $200–$1,500 depending on the city. Check your local rules before you build — a stop-work order costs far more than the permit.
Sizing the stone underneath? Use the gravel calculator and read how much gravel for a shed base.