Sheds in SA: Council Approval Rules and the Slab That Holds It All Down

Two things decide whether your shed project goes smoothly in South Australia: whether the paperwork was done before the concrete, and whether the concrete was done before the frame. Here's both, in plain terms.

When a shed needs approval in SA

A domestic shed or similar outbuilding is generally exempt from approval only when all of these hold: floor area up to 15 m², height no more than 2.5 m, sited behind the building line, not in a heritage/character area or special overlay, and clear of easements. That 15 m² ceiling is small — a 5×3 m garden shed. Which means in practice:

• Almost every single garage (≈18 m²+), double garage (≈36 m²) and workshop needs development approval.
• Carports attached to the house need approval as structures attached to a dwelling, and even freestanding ones commonly exceed exemption limits or sit forward of the building line.
• Heritage and character zones (and the Hills Face Zone) remove exemptions entirely — relevant across Unley, Norwood, Prospect and Colonel Light Gardens.

Applications run through the PlanSA portal with site plans and the shed manufacturer's engineering. Councils also want to see stormwater disposal — where those big roof areas will drain — resolved on the plans.

Wind rating: the spec nobody checks

Every legitimate shed kit is engineered to a wind classification (N1–N4 for most Adelaide sites, higher in exposed Hills and coastal locations). The classification changes member sizes, bracing, and — critically — the footing and hold-down design. A kit priced for suburban N2 is not the same product as one engineered for a gully-line block in Stirling or a cliff-top street in Hallett Cove. If your quotes differ oddly, compare wind ratings first.

The slab is the anchor

Wind doesn't blow sheds over; it lifts them. The slab resists that uplift, which is why the manufacturer's engineering specifies cast-in hold-down bolts at exact template positions, edge thickenings under columns, and minimum slab thickness — commonly 100 mm with SL72 mesh for garden sheds, 125 mm with thickened edges for garages and workshops.

The most common defect we're asked to rescue: a slab poured "close enough", with columns later fixed on drilled-in anchors, off-template, in thin edge concrete. It's weaker in exactly the load case that matters and it voids the kit's engineering. Pour the slab for the frame — bolts cast in, square, level — and the frame stands plumb in a day.

One contract beats three

Kit from one supplier, slab from a concreter, erection by a handyman, approval by nobody — when dimensions don't line up, everyone points elsewhere. We supply and install sheds and carports as a single contract: approval, slab, frame, sheeting and stormwater, one scope, one handover.