Cost guide 2026
What a granny flat really costs in Brisbane
No teaser pricing, no "from $99k*" games. Here are the honest turnkey ranges Brisbane homeowners are actually paying, what moves the number, and how to compare quotes like a pro.
Brisbane granny flat costs by size
These ranges are for turnkey builds: designed, approved, built, connected to services and ready to live in. Assumes a reasonably standard Brisbane block; sloping or difficult sites push toward and past the upper end.
| Type | Size | Typical turnkey cost | Typical rent* |
|---|---|---|---|
| Studio | approx 45 m² | $120,000 - $160,000 | $350 - $470 / week |
| 1 bedroom | approx 60 m² | $145,000 - $190,000 | $400 - $550 / week |
| 2 bedroom | approx 70 m² | $170,000 - $250,000+ | $500 - $650 / week |
*Rent figures are indicative Brisbane ranges by suburb and specification, not a guarantee. Check current listings in your suburb and see the rental and investment page.
What pushes the price up (or down)
- Slope. The single biggest variable. A flat block takes a slab; a sloping block needs a steel sub-floor or cut-and-fill, which can add tens of thousands. Common in The Gap, Ferny Grove and parts of Mount Gravatt.
- Service runs. Power, water and sewer have to reach the granny flat. Short runs from the main house are cheap; long runs, boundary connections or a required upgrade to the main switchboard are not.
- Access. If a truck and bobcat can reach the backyard, earthworks are quick. If everything comes through a 900 mm side gate by hand, labour goes up.
- Wet areas. Kitchens and bathrooms are the most expensive rooms per square metre. A second bathroom adds real money; a longer living room adds comparatively little.
- Specification. Stone benches, higher ceilings, ducted air, hardwood decks: all legitimate choices, all additive. A rental-grade spec and an owner-occupier spec can differ by $20,000+ on the same floor plan.
- Approvals and reports. Building approval, soil test, engineering and certifier fees typically run a few thousand dollars combined, more if a planning application or overlay assessment is needed.
The extras people forget to budget
- Driveway or path to the granny flat entry, and any parking space you want to provide
- Fencing and screening to give the flat (and the main house) privacy - often required for a comfortable rental
- Separate metering or sub-metering for power and water if you plan to rent it out
- NBN / internet connection - tenants expect it from day one
- Landscaping and clothesline - small items, but they decide how fast it rents
- Landlord insurance and rates impact - talk to your insurer and check how council treats the addition
How to compare builder quotes
- Demand line items. A single-number quote hides exclusions. You want site works, services, approvals, and finishes itemised.
- Check the provisional sums. Allowances for earthworks or rock removal that look suspiciously small usually are. Ask what happens if they are exceeded.
- Confirm licensing and insurance. Verify the builder's licence on the QBCC's free online register, and confirm Queensland Home Warranty Scheme cover applies to the work (it is generally required for residential building work over $3,300 including granny flats - your builder arranges it).
- Compare like with like. A turnkey quote against a kit-plus-assembly quote is not a fair fight until you add everything the kit excludes.
- Get it in a proper contract. Residential building work in Queensland should be on a compliant written contract with staged payments. No handshake builds.
The honest bottom line: for a finished, approved, connected granny flat in Brisbane, budget somewhere between $120,000 and $250,000+ depending on size and site. Anyone quoting far below that range is excluding things you will end up paying for anyway.