Our 3D check covers Victoria, NSW and Queensland. Here’s the short version for every state.
Fast-track approval through a Complying Development Certificate on residential lots of 450 m² or more. Smaller lots, or a bigger flat, go through a council DA.
Rent it to anyone. Can’t be subdivided off.
NSW Planning: secondary dwellings Check a NSW address in 3DEach council sets the size. Brisbane allows around 80 m². Most meet the council code without a DA, but building approval is always needed.
Rent it to anyone since September 2022. Stays part of the house, can’t be sold separately.
Queensland: changes to secondary dwellings Check a Queensland address in 3DUp to 70 m² and two bedrooms, with its own kitchen, bathroom and laundry. Deemed-to-satisfy in most suburban zones.
Stays ancillary to the main house on the same site.
SA: bigger, more accessible granny flatsNo development approval needed since April 2024, as long as it meets the R-Codes deemed-to-comply standards. Still needs a building permit.
Rent it to a relative, a friend or someone you don’t know.
WA Planning: granny flat info sheet (PDF)A secondary residence of up to 90 m² on blocks of 500 m² or more, usually through a development application. The rules changed again on 1 July 2026, so check the current version.
Can’t be unit titled unless the block is approved as a dual occupancy.
ACT Planning: secondary residence guide (PDF)Up to 60 m², sharing access, parking and meters with the house. Often no planning permit if it meets the zone’s acceptable solutions. A change to 90 m² was proposed in 2026.
Building permit always needed.
Tasmania: secondary residences amendmentCalled an “independent unit”. Up to 75 m² in some zones, with no planning approval if it meets every scheme requirement.
No unit-title subdivision.
NT: building an independent unitNo planning permit in most cases. Check your own block in 3D, with your lot, zone and overlays.
Check a Victorian addressThe rent and ROI calculator works anywhere in Australia.
Summary checked October 2026. Councils and states change these rules, so confirm with your council or certifier before you build.