Shed and outbuilding certification

Size and setback limits

An exempt shed in a residential zone can have up to 20 m² of floor area and must sit 900 mm or more from every boundary. In large-lot residential and most rural zones, the cap is 50 m², with a setback of 5 m or more from every boundary. Whatever the zone, its height above ground is limited to 3 m.

The exempt route may be closed to you on environmentally sensitive land, or where heritage items or heritage conservation areas are involved. Before relying on it, read your planning certificate (the council document setting out the controls on your land).

If your shed misses these limits, it needs approval. Council's local planning controls may then set different size limits by zone and lot size.

Building on bushfire prone land

On bushfire prone land, an exempt shed must use non-combustible materials. Check the frame, cladding and lining against your property's bushfire mapping before you order a kit.

Where approval is needed and the shed is on bushfire prone land no more than 6 m from a building, it must comply with the NSW bushfire planning rules. Complying development is not an option where the land is rated BAL-FZ (flame zone) or BAL-40, so a shed there needs a development application (DA) lodged with council.

Can my shed be a studio or office?

Only with approval. A shed is classed as non-habitable, so it is not meant for living or working in. An exempt shed cannot serve as living space, and turning one into a studio or home office requires planning approval.

Once a building is used for living or working, it must meet the building code rules for habitable rooms. These cover ceiling heights, natural light, ventilation, smoke alarms and energy efficiency. A storage shed never had to meet them. Where the type of building is unclear, the approval authority decides. Plan the use at the start. Upgrading a finished shed is much harder.

Water, sewer and stormwater

Exempt status covers the shed itself, not every connection to it. Adding water or sewer needs approval from the water utility, council or both. A stormwater connection can need council approval. A plumbed shed is often a sign its use is changing, so think that through before work starts.

Can a shed sit over a sewer pipe?

In Sydney Water's area, a light outbuilding can sometimes be placed over a sewer main. Its technical guidelines allow carports, verandahs, decks, sheds, pergolas and similar structures over a reticulation sewer with a diameter of 300 mm or less. The structure must not be habitable or a place of business, must be readily removable, and must have an area no greater than 36 m².

Footings have to stay 600 mm or more from the pipe wall and from any sewer maintenance structure's wall. A footing may sit directly above the pipe only where more than 750 mm separates the underside of the footing from the top of the pipe, and the design load at footing level is no more than 50 kPa.

The same guidelines say these lightweight structures cannot be permanently enclosed. A fully clad garden shed over a sewer may therefore fall outside that category, so check the position with Sydney Water before the slab is poured.

Keep sewer access points clear

Nothing may be built over a sewer maintenance hole or other maintenance structure, and property connection points cannot end up under a shed. Sydney Water must be able to reach its pipes without having to move or remove your building.

Around a maintenance hole, the guidelines ask for a clear working space of at least 1 m around the rim with 2.4 m of headroom, and an unobstructed path to it at least 1 m wide. A lid hidden under soil, a garden bed or a structure is not acceptable.

Before setting out the slab, buy the Sydney Water service diagram for the property and check for underground services through Before You Dig Australia. Where the shed needs council or certifier approval, Sydney Water also has to approve the plans before any building or excavation begins.

Removing an old fibro shed

If an old shed has fibro sheeting, find out whether it contains asbestos before you pull it down. What you may do yourself turns on two things: whether the asbestos is bonded or friable, and the area involved.

A homeowner may take down bonded (non-friable) asbestos sheeting without a licence, provided the area is under 10 m². Larger areas of bonded sheeting, and friable asbestos in any quantity, are jobs for a licensed removalist. Friable material is work only for a removalist licensed at Class A, who must seal off the area and carry out air monitoring.

Disposal must be at a licensed landfill site that takes asbestos waste. Some removal work also calls for a clearance certificate from a licensed asbestos assessor or removalist, so check with council about what it needs before the replacement shed's slab goes down.

If a shed was built without approval

A shed that needed approval but never got it can sometimes be regularised with a building information certificate. These come from council, on application. With it in hand, the owner has council's assurance that it will not order that the shed, or the portion covered, be pulled down, changed, extended or rebuilt.

Expect to supply owner's consent, as-built plans, a statement describing the works, and an identification survey from a registered surveyor showing where the shed sits against the boundaries. Council can request more, such as an engineer's certificate for the structure, a building code report or other compliance evidence.

Approval is not guaranteed. Where the evidence does not satisfy council, it may respond with a direction to remove or alter it. A buyer who has signed a sale contract can also apply for one of these certificates, so an unapproved shed is best dealt with before a property goes to market.