What our analysis shows
Analysis by Granny Flat Numbers, data as of 23 October 2026
- A standard 60 m² two-bedroom flat comes to $198,500 turnkey in Brisbane ($174,500–$222,500) and $169,500 in regional cities such as Townsville or Cairns.
- The Gold Coast gives the fastest payback of any area in our national data: 8.4 years on a 60 m² flat, on a median two-bedroom rent of $750 a week from Residential Tenancies Authority bonds.
- One-bedroom flats are a poor bet outside the inner suburbs. In Townsville a one-bedroom flat rents for 62% of a two-bedroom house; in Logan, 63%. That penalises Moreton Bay owners most, where the 45 m² cap on standard lots rules out a real second bedroom.
- An infrastructure charge can only come with a development approval. A flat that is accepted development, which in Brisbane means up to 80 m² and within 20 m of the house, avoids it. If yours needs a DA, Brisbane's adopted charge for a one- or two-bedroom dwelling is $13,424 from 1 July 2026, before any credit for the existing house.
Fastest payback in Queensland, 60 m² two-bedroom flat
- Gold Coast8.4 years
- Cairns9.0 years
- Brisbane9.7 years
- Sunshine Coast9.7 years
- Townsville10.4 years
- Toowoomba11.4 years
- Moreton Bay12.1 years
- Logan12.7 years
- Ipswich12.7 years
- Redland13.0 years
After agent fees, insurance, maintenance and tax at 30%, no loan. Rents: RTA median for new bonds by council area, September quarter 2026 (1-bed flat, 2-bed house).
What you pay for
| Line, 60 m² in Brisbane | Cost |
|---|---|
| Construction | $162,000 |
| Site preparation (flat, easy access) | $12,000 |
| Sewer, water, power and stormwater connections | $10,000 |
| Design, engineering and BASIX/energy report | $8,000 |
| Approval: Building approval (accepted development) | $6,500 |
| Total | $198,500 |
The approval line covers a private certifier's building approval, council plumbing approval and the energy report. Many Queensland blocks are sloping or need a suspended slab or stumps; on a sloping Brisbane lot our model adds $13k to $33k.
| Size | Budget | Standard | Premium | Standard, regional |
|---|---|---|---|---|
| Studio, 35 m² | $120,500 | $139,500 | $170,500 | $121,000 |
| 1 bed, 45 m² | $138,500 | $161,500 | $199,000 | $139,000 |
| 2 bed, 60 m² | $169,000 | $198,500 | $247,000 | $169,500 |
| 2 bed, 70 m² | $191,000 | $225,500 | $282,000 | $191,500 |
| 2–3 bed, 80 m² | $213,000 | $252,500 | $317,500 | $213,500 |
The council cap decides the deal
We priced the largest flat each council allows on a standard suburban lot and matched it to local rent. Below 55 m² we used one-bedroom rent, because a second bedroom does not fit in a liveable plan.
| Council | Largest flat | Cost | Rent / week | Payback |
|---|---|---|---|---|
| Brisbane | 80 m², 2 bed | $252,500 | $650 | 12.3 yrs |
| Gold Coast | 80 m², 2 bed | $252,500 | $750 | 10.6 yrs |
| Logan (lot under 1,000 m²) | 70 m², 2 bed | $225,500 | $500 | 14.4 yrs |
| Sunshine Coast | 60 m², 2 bed | $198,500 | $650 | 9.7 yrs |
| Ipswich (lot 450–600 m²) | 60 m², 2 bed | $198,500 | $500 | 12.7 yrs |
| Moreton Bay (lot 450–800 m²) | 45 m², 1 bed | $161,500 | $340 | 15.5 yrs |
Building to the cap is not the same as building the best investment. In Brisbane the 80 m² flat takes 12.3 years to pay back against 9.7 for 60 m², because tenants pay for bedrooms, not floor area. Moreton Bay owners get the weakest result: the small flat is cheaper, but a one-bedroom flat there rents for $340, so the payback is the longest in the region. On lots over 800 m² Moreton Bay allows 55 m², which lifts the case. Caps change when planning schemes are amended, so confirm yours with council before you design.
Rent and payback
| Area | 1-bed rent | 2-bed rent | 60 m² build | Net yield | Payback |
|---|---|---|---|---|---|
| Gold Coast | $615 | $750 | $198,500 | 16.2% | 8.4 yrs |
| Cairns | $420 | $600 | $169,500 | 14.9% | 9.0 yrs |
| Brisbane | $590 | $650 | $198,500 | 13.8% | 9.7 yrs |
| Sunshine Coast | $500 | $650 | $198,500 | 13.8% | 9.7 yrs |
| Townsville | $320 | $520 | $169,500 | 12.8% | 10.4 yrs |
| Toowoomba | $350 | $480 | $169,500 | 11.7% | 11.4 yrs |
| Moreton Bay | $340 | $525 | $198,500 | 10.9% | 12.1 yrs |
| Logan | $315 | $500 | $198,500 | 10.3% | 12.7 yrs |
| Ipswich | $370 | $500 | $198,500 | 10.3% | 12.7 yrs |
| Redland | $400 | $490 | $198,500 | 10.1% | 13.0 yrs |
Rent data: Residential Tenancies Authority median rents, September quarter 2026. The RTA does not split houses by whether they are a granny flat, so one-bedroom rent is for flats and units. In NSW, where we could separate them, detached one-bedroom dwellings rented for less than flats in Sydney and about the same in regional areas.
Infrastructure charges
Builder guides disagree widely on what Queensland councils charge for a granny flat, from nothing to over $20,000. The rule behind it is simple. Under the Planning Act a council issues an infrastructure charges notice with a development approval. A flat that is accepted development under the planning scheme needs no development approval, so no charge is issued.
When a DA is needed, the charge depends on the council's charges resolution. Brisbane's Resolution No. 15 (from 1 July 2026) sets $13,424 for a one- or two-bedroom dwelling and $18,793 for three or more bedrooms; the council may credit demand from the existing house. Ask the council for the figure before you lodge, and budget for it if your flat exceeds the cap or setbacks.
Queensland-only costs
- QBCC home warranty insurance. Payable on residential building work over $3,300; the builder includes it in the price, typically $1,500–3,500 for a granny flat.
- Water and sewer connection. Urban Utilities (Brisbane, Ipswich, Logan) and Unitywater (Moreton Bay, Sunshine Coast) charge for connection approvals and any new meter, separately from council.
- Owner-builder permit. If you manage the build yourself and the work is over $11,000, you need a QBCC owner-builder permit and course.
This week's worked example
Week of 19 October 2026. A new example, rule and owner report every Monday.
A 65 m² two-bedroom flat with a standard finish on a flat block, services 12 m from the house, in Cairns: our model puts it at $180,500 turnkey ($159,000–$202,000), or $2,780 per m². At the area's median 2-bedroom bond rent of $600 a week it would return 14.0% net and pay back in 9.6 years after tax.
Rule check: Since 26 September 2022 a Queensland secondary dwelling can be rented to anyone, not only to relatives of the main household.
From an owner (QLD, 2025): Another Brisbane-area owner found prefab units of any quality priced close to a small new three-bedroom house, and gave up.
Questions people ask
How much does a granny flat cost in Brisbane?
About $198,500 turnkey for a standard 60 m² two-bedroom flat; $252,500 for 80 m², the most Brisbane allows as accepted development.
How big can a granny flat be in Queensland?
It depends on the council: 80 m² in Brisbane and the Gold Coast, 70 m² in Logan on lots under 1,000 m², 60 m² on the Sunshine Coast, 60–120 m² in Ipswich by lot size, and 45–55 m² in Moreton Bay.
Can I rent my granny flat to anyone in Queensland?
Yes. Since 26 September 2022 a secondary dwelling can be rented to anyone, not only to family of the main household.
Do I pay infrastructure charges on a granny flat in Queensland?
Only if the flat needs a development approval; charges are issued with the approval. Brisbane's charge for a one- or two-bedroom dwelling is $13,424 (Charges Resolution No. 15, 2026). Water and sewer connection charges from Urban Utilities or Unitywater are separate.