What our analysis shows
Our calculations, data as of 23 October 2026
- A standard 60 m² two-bedroom flat costs $187,000–$237,600 turnkey across the states and the ACT in our model.
- In Sydney a detached one-bedroom dwelling rented for a median $550 a week in July–September 2026, against $719 for a one-bedroom flat.
- Payback after tax, with no loan, runs from 8.4 to 15.2 years across the 42 areas with government rent data.
How much does a granny flat cost in Australia?
A standard 60 m² two-bedroom flat costs $187,000–$237,600 turnkey in our model, from South Australia to the Australian Capital Territory. Site, connections and approval are included. See the cost calculator.
What is the cheapest way to get a granny flat?
A kit managed by an owner-builder: about $151,600 for 60 m² in Sydney against $220,000 through a builder. Prefab is only slightly cheaper than site-built, and only above about 50 m². Compare kit, prefab and builder.
How big can a granny flat be?
60 m² in NSW (unless the council allows more), 80 m² in Victoria's planning rules from 15 October 2026, 70 m² in WA and SA, 90 m² in the ACT, 60 m² in Tasmania, and 45–120 m² in Queensland depending on the council. Check the rules by state.
Do I need council approval?
Always a building approval. Planning approval depends on the state and design: fast-track routes skip a council assessment in NSW (CDC), Victoria, WA, SA and many Queensland councils, but not in the ACT. Check the rules by state.
How much rent does a granny flat earn?
From government bond data: $370–$750 a week for two bedrooms across 42 areas. In Sydney a detached one-bedroom dwelling rented for $550, below the $719 for a one-bedroom flat. See rents by area.
How long does a granny flat take to pay for itself?
8.4 to 15.2 years after tax with no loan in our data, fastest on the Gold Coast. Run the yield calculator.
Is a granny flat worth it?
After tax and an allowance for the building wearing out, it beat paying down a 6.2% mortgage in about six of every ten areas we tested; in outer suburbs and some regional cities it did not. See the offset test.
Does a granny flat increase land tax?
It can. Victoria taxes the flat's part of the land from 2026; in NSW a 2025 tribunal decision narrowed the exemption for detached rented flats. Thresholds protect many owners without other investment property. Read the land tax guide.
Can I rent my granny flat to anyone?
Yes, in every state and territory. Queensland removed its family-only rule on 26 September 2022. See the rules by state.
Can a granny flat be sold separately?
No. It stays on the same title as the main house in every state; subdividing it off needs a different approval as a separate dwelling, where that is allowed at all. Read how value is affected.
Can my parents pay for a granny flat on my land?
Yes. Centrelink does not treat paying to build a granny flat on someone else's land, in return for a life right to live there, as gifting. Put the arrangement in writing. Read the guide for parents.
How do I get internet to a granny flat?
Either share the main house's connection through a cable or fibre run in conduit, or register the flat's address and apply to NBN for a second location. Lay the conduit during the build. Read what owners report.