Putting up a shed: the kit, the slab and the approvals
The three parts of a shed's cost, why the slab is often a third of it, and how to hire a shed builder and handle any approval.
A shed looks like a single purchase but it's really three: the kit, the slab it stands on, and the labour to put it up. People price the kit, forget the slab, and get a nasty surprise — because on anything garage-sized the concrete can be a third of the total. Understanding the three parts is the whole trick to budgeting a shed properly.
The other surprise is approvals. A small garden shed usually slips under the radar, but a bigger structure often needs council or private certifier sign-off before a single sheet goes up. Knowing where that line sits saves a stalled project.
What a shed project involves
The kit is the steel structure — frame, cladding, roof, doors and any windows. A small garden shed can sit on pavers or a timber floor, but anything garage-sized needs an engineered concrete slab sized and reinforced for the structure and what goes in it. The slab is poured first and cured before erection, and it's frequently the single biggest line in the budget.
Erection is the labour to assemble and fix the shed to the slab, square and weathertight. Size, steel gauge and inclusions drive the kit price — roller doors, personal access doors, windows, insulation and higher wind ratings all add up. And beyond a certain size or in certain zones, the project needs approval, so the paperwork is part of the job, not an afterthought.
How the cost works
Shed pricing splits across the three parts. A basic garden shed supplied and installed is a modest job; a garage-sized shed with an engineered slab is a much larger one, with the concrete a substantial share of it. Larger farm or workshop sheds climb well beyond that.
The levers are size, steel gauge, door and window inclusions, insulation, and the wind rating your area demands — a shed in a high-wind zone needs a stronger structure and heavier slab. Site prep matters too: a sloping or poorly draining site adds excavation and fill before the slab goes down. Treat figures as indicative; size, inclusions and site conditions drive a quote that a site assessment makes real.
Choosing a shed builder and handling approval
Shed building sits in structural territory, and licensing is state-dependent — larger sheds and the concrete and structural work often require a builder's licence, while a small garden shed may not. Ask what licence applies to your size of shed in your state, and confirm who's responsible for the slab, since a shed is only as sound as the base under it.
Approvals are the part to pin down early. Depending on size, location and your council, a shed may need development or building approval, and a good builder tells you whether yours does and who lodges it. Engineering certification for the slab and structure is worth having in writing — it matters for insurance and resale. Get the split of responsibilities clear: kit supply, slab, erection and paperwork should each have an owner in the quote.
Mistakes to avoid
Shed regrets are almost always the forgotten slab, the skipped approval, or a structure under-specced for the wind zone. Each is a planning miss rather than a build fault, and each is settled before anyone pours concrete.
- Budgeting for the kit and forgetting the slab is often a third of the cost
- Not checking whether your shed size and location need council or certifier approval
- Ordering a shed under-rated for your area's wind zone
- Assuming the kit price includes the slab, erection and site preparation
- Skipping engineering certification you'll want for insurance and resale
- Choosing thinner steel gauge to save upfront on a shed meant to last decades
Indicative range only, not a quote — see the full guide for worked scenarios and what moves the price.
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