Does my shed need a building permit?

Threshold — the opening words

The work has to be construction

Item 1 exempts the construction of a building. Under the Building Act 1993 that reaches building, erecting or re-erecting, repairing, altering, enlarging or extending a building, and placing or relocating one on land — so taking delivery of a pre-built shed, adding to an existing one or shifting one across the yard is all construction, and the shed has to satisfy every condition in its finished state.

Demolition and removal are not construction. They sit under item 2 of the same Table, on different tests: not constructed of masonry, floor area not exceeding 40 m², will not adversely affect the safety of the public or of occupiers, and not work on or in connection with a building on the Heritage Register.

Threshold — the opening words

It has to be freestanding

Freestanding is not defined in the Regulations. In its ordinary sense it means standing on its own, not attached to or structurally dependent on another building. A structure sharing a wall, a roof, a gutter, a fascia or a footing with the house, the garage or an existing carport is not freestanding, and item 1 is not available to it at any size.

That does not mean an attached structure needs a permit. Other items in Schedule 3 have no freestanding requirement — item 16 exempts a pergola not more than 3.6 m in height with a floor area not exceeding 20 m², and allows it up to 2.5 m forward of the front wall of a Class 1 building. A pergola, though, is defined in the Regulations as an open structure that is unroofed, so a roofed structure is a different question again, and it has its own page.

Threshold — the opening words

It has to be a Class 10a building

Class 10a is a non-habitable building — a private garage, carport, shed or the like. The word carrying the weight is non-habitable. Classification follows the purpose a building is designed, constructed or adapted for, and each part of a building is classified according to its own purpose, so a shed with a lined, plumbed or slept-in corner is not saved by the rest of it being storage.

This is the condition most often missed, because a backyard studio, home office, gym or sleepout is still bought and delivered as a shed. Where the structure is not Class 10a, item 1 does not engage at all — the floor area and height figures below never come into it.

Paragraph (a)

Floor area not exceeding 10 m²

Not exceeding, so exactly 10 m² is inside the condition. Use the kit's real dimensions rather than a rounded brochure size: 3 m × 3 m is 9 m² and comfortably inside; 3.2 m × 3.2 m is 10.24 m² and outside it. Floor area is not defined in the Regulations, so whether an eave, an awning, an open annexe or a lean-to counts is a judgement — and regulation 7 requires the prescribed figures to be applied subject to tolerances according to normal trade practice or good practice, which means a shed sitting on the line is a matter for the surveyor rather than a calculator.

Paragraph (b)

Height: no more than 3 m, or 2.4 m within 1 m of a boundary

The building must be no more than 3 m in height, or, where it is situated within 1 m of a boundary, no more than 2.4 m. The lower figure is the one that catches people: a standard gable garden shed tucked against the fence often clears 2.4 m at the ridge even where its walls are well under it.

How height is measured is where the answers go wrong. Height is the vertical distance from natural ground level to the top of the roof covering, at any point. Natural ground level means the ground in its pre-development state — not the slab, not the pad, not the finished floor. At any point means the maximum governs, so on a sloping block the downhill corner decides it: a nominally 2.4 m shed across a 300 mm fall is 2.7 m at the low corner. Measure to the ridge, not the eave and not the wall height quoted on the brochure. Chimneys, flues and service pipes are left out.

Note what this paragraph is not. There is no minimum setback from a side or rear boundary anywhere in item 1. Boundary proximity appears once, here, and only to decide which of the two height limits applies. As far as item 1 is concerned a compliant 2.4 m shed can sit hard against the fence. Any boundary counts — side, rear or front — and it is the title boundary, which does not always follow the existing fence.

Paragraphs (c) and (d)

Then one of two limbs, and the switch is what the shed serves

Paragraphs (c) and (d) are alternatives. Exactly one of them applies, and the question that picks between them is whether the building is appurtenant to a building of another Class on the same allotment — belonging to and serving it. Not whether there is a house on the block, which is how the rule is usually paraphrased and is not what it says. A block can carry a house and still fall into limb (d), where the shed does not serve it or the house sits on a different title. Allotment is a title concept — land that can be disposed of separately — so a house on the neighbouring title does not help. And the reference building need not be a house: on a commercial, industrial or farm allotment it is the shop, warehouse or factory.

Limb (c) — appurtenant to a building of another Class on the same allotment. The shed must be located no further forward on the allotment than the front wall of the building it is appurtenant to. No further forward than, so level with the front wall is inside the condition. Front wall is not defined, and a porch, portico, bay window, projecting garage or stepped facade makes the reference plane a judgement.

Limb (d) — not appurtenant to a building of another Class on the same allotment. Three requirements, all of which must be met: it must be the only Class 10a building on the allotment (an existing carport, garage or old shed defeats it outright, however small); it must be set back at least 9 m from the front street alignment; and it must be set back at least 2 m from each side street alignment. At least, so exactly 9 m and exactly 2 m are inside the conditions.

The street alignment is the line between a street and an allotment — your title boundary with the street. Not the kerb, not the road edge, not the far side of the nature strip, not the front fence; measuring from any of those typically flatters the setback by several metres. And street is defined broadly: it includes a road, highway, carriageway, lane, footway, square, court, alley and right of way, so a rear laneway is a street with a street alignment of its own, on a lot nobody would describe as a corner block.

Paragraph (e)

Not constructed of masonry

Masonry is not defined in the Regulations. In its ordinary building sense it is brick, concrete block, stone and the like laid in units, and rendered blockwork or concrete panel is plainly within it. A steel or timber-framed kit is plainly outside it. A plain concrete slab on the ground is generally read as the floor rather than as the building being constructed of masonry, but nothing in the Regulations settles that, and a masonry base course, dwarf wall or set of piers under a framed shed is a genuine judgement rather than a yes or no.