Building a granny flat costs about $3,240 to $3,990 per m² all-in in 2026, depending on the state. That is the full price, including GST, design, permits and connections, not the building-only rate builders often advertise.
Standard finish, builder-built, easy flat block, including GST, design, permits, connections and basic landscaping. South Australia, the ACT and the NT have fewer published prices, so treat those as rougher.
| State | Per m², all-in | 60 m² two-bedroom | Fast-track size limit |
|---|---|---|---|
| Victoria (Melbourne) | $3,590 | $176,000– | 60 m² |
| NSW (Sydney) | $3,990 | $194,000– | 60 m² |
| Queensland (Brisbane) | $3,240 | $158,000– | set by council |
| WA (Perth) | $3,290 | $158,000– | 70 m² |
| SA (Adelaide) | $3,290 | $158,000– | 70 m² |
| Tasmania (Hobart) | $3,640 | $176,000– | 60 m² |
| ACT (Canberra) | $3,840 | $188,000– | 90 m² |
| NT (Darwin) | $3,890 | $188,000– | 75 m² in some zones |
A kitchen and a bathroom cost about the same in a 30 m² studio as in a 60 m² two-bedroom flat. Spread over fewer square metres, the rate goes up. In Melbourne a 30 m² studio works out around $4,600 per m², against $3,590 for 60 m².
Builders often quote $1,800 to $2,600 per m² for the building alone. That leaves out design, permits, connections and site works, which add $20,000 to $50,000 on an easy block. Compare like with like.
About $3,200 to $4,000 per m² all-in for a 60 m² two-bedroom granny flat in 2026, from about $3,240 in Brisbane to about $3,990 in Sydney.
Queensland, WA and SA come out cheapest per m², around $3,240 all-in. NSW is the most expensive at around $3,990.
They are usually building-only rates. Design, permits, the surveyor or certifier, connections and landscaping come on top, adding $20,000 to $50,000 on an easy block.
Yes. The kitchen and bathroom are fixed costs, so a 70 m² flat costs less per m² than a 45 m² one, even though the total is higher.
About $158,000–$231,000 in Brisbane, $176,000–$255,000 in Melbourne and $194,000–$285,000 in Sydney, all-in.
Put this price and your expected rent into the rent and ROI calculator to see the yield and payback time.
Prices are all-in estimates including GST, from our cost calculator, which is built on 2026 builder price lists and cost guides. Checked 25 October 2026. Get at least two quotes after a site visit.