A building approval is the cheaper of the two by a wide margin. In South East Queensland the certifier's own fee for a granny flat approval runs about $700 to $2,400 ex GST, and the approval all in, with the reports the certifier needs and the council plumbing permit, about $5,500 to $8,200 ex GST when no planning application is involved. A planning application adds the council's application fee, which in Brisbane is $1,500 for a secondary dwelling in 2026-27, plus a town planner and whatever reports the overlay asks for. Then come the charges that are not approvals at all but land at the same time: home warranty insurance and the QLeave levy on a licensed builder's job, and in some councils an infrastructure charge.
The building approval path
| Line | Cost | Where the number comes from |
|---|---|---|
| Building certifier | About $700 to $2,400 ex GST | 2026 certifier quotes for a granny flat approval, South East Queensland |
| Plumbing permit, Brisbane | $300 to lodge plus $1,290 for up to five inspections | Brisbane City Council plumbing and drainage fees 2026-27, sewered new secondary dwelling. An on-site sewage facility adds a $300 assessment |
| Reports the certifier needs | Engineering about $2,650, soil test about $900, energy report about $650, survey $2,400 to $3,850 | Installer rates, inc GST. The consultants lists each one |
| Approval all in, no DA | About $5,500 to $8,200 ex GST | Typical granny flat, 2026 installer figures |
What a planning application adds
The council fee first. Brisbane's 2026-27 schedule prices a code assessable secondary dwelling as Domestic type B, a flat fee of 10 points, $1,500 ex GST. Other councils set their own fee schedules each July. Then the work of making the application: a town planner to write it, and the reports the overlay asks for. A BAL assessment is about $1,000. A flood report runs about $1,300 to $6,600 depending on what the engineer has to model. A planner's fee is not published anywhere official, so get it quoted. A planning application also takes time, and time on a construction loan is a cost of its own.
The charges that arrive with the approvals
- Home warranty insurance. Compulsory when a licensed contractor does residential work worth more than $3,300, paid by the builder and priced into the job. On the QBCC's published table the premium is $644.20 on $100,000 of insurable value, $876.80 on $150,000 and $1,109.45 on $200,000. An owner builder does not pay it and does not get the cover.
- QLeave and the two levies with it. 0.575% of the cost of building work of $150,000 or more, paid before the building approval issues. Under $150,000, nothing. Most single-module installs sit under the line; the home plus a licensed install often crosses it.
- Infrastructure charges. Set by each council's charges resolution, up to the state cap of $26,193.40 for a dwelling with two bedrooms or fewer and $36,670.70 for three or more. Logan charges a secondary dwelling at those amounts. The Gold Coast exempts one up to 80 m², Redland charges only above its caps, Ipswich and Noosa charge none. What a granny flat costs in my council has the table.
Owner builder or licensed builder changes the total
Certification and approvals on a modular install come to about $25,000 with the owner as the owner builder and about $35,000 with a licensed builder signing. The difference is the home warranty premium, the levy and the builder's margin on a home someone else made. Can I be the owner builder? sets out the trade.
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Questions people ask next
How much does a building approval cost for a granny flat in Queensland?
The certifier's fee is about $700 to $2,400 ex GST. With the engineering, soil test, energy report and the council plumbing permit, a granny flat approval with no planning application comes to about $5,500 to $8,200 ex GST, from 2026 South East Queensland figures.
How much does a planning application cost?
The council fee plus a planner and reports. Brisbane charges $1,500 ex GST for a code assessable secondary dwelling in 2026-27. A BAL assessment is about $1,000 and a flood report $1,300 to $6,600. Planners' fees are not published, so get one quoted.
Is there an infrastructure charge on a granny flat?
It depends on the council. The state caps the charge at $26,193.40 for a dwelling of two bedrooms or fewer and $36,670.70 for three or more. Logan charges those amounts, the Gold Coast exempts a secondary dwelling up to 80 m², and Ipswich and Noosa charge none.
- Brisbane City Council, development assessment and compliance fees 2026-27 (Domestic type B, secondary dwelling, 10 points $1,500), read 16 October 2026
- Brisbane City Council, plumbing and drainage fees 2026-27 (new secondary dwelling, sewered: $300 application, $1,290 inspections), read 16 October 2026
- QBCC, Queensland Home Warranty Scheme premium table, construction of a new residence, read 16 October 2026
- QBCC, what is the Queensland Home Warranty Scheme ($3,300 threshold), read October 2026
- QLeave, what is the levy (0.575% on work of $150,000 or more), read 16 October 2026
- Planning (Prescribed Amounts) Amendment Regulation 2025, schedule 16 (maximum infrastructure charges from 1 July 2025), read 16 October 2026
- City of Gold Coast, infrastructure charges resolution (secondary dwelling up to 80 m² exempt), read October 2026
- Logan City Council, domestic housing fact sheet (secondary dwelling charged as a dwelling), read October 2026
- Installer rates behind the install cost calculator (certifier, reports, approvals all in), read 16 October 2026