QLD planning resource · Free plan check

Can I build a granny flat in Brisbane?

In Queensland a granny flat is a 'secondary dwelling'. The Brisbane City Plan sets clear numbers for what's allowed — size, location, parking — and whether you need a development application. Read the rules below, then check your plans against them free.

Brisbane homeowners weighing up a granny flat / secondary dwelling for family, rental income or a home office — who want to know what's allowed before paying for design.

Check your granny flat plans free Free QLD Council Finder

What the Brisbane City Plan allows

Queensland planning calls a granny flat a 'secondary dwelling' — a self-contained dwelling on the same lot as the main house. The Brisbane City Plan Dwelling House Code (9.3.7) sets out exactly one secondary dwelling per lot, each occupied by a single household. Get the numbers right and a secondary dwelling can be 'accepted development' — meaning no development application is needed; miss one and it becomes assessable development requiring a DA.

The two numbers that decide most projects: the secondary dwelling must be a maximum of 80 m² gross floor area, and located within 20 m of the main dwelling house (Acceptable Outcome 1.2). Height and storeys follow the zone — generally 9.5 m and 2 storeys in the low-density residential zones — and one extra on-site car space is required.

One secondary dwelling per lot, in addition to the main house
Maximum 80 m² gross floor area (AO1.2)
Within 20 m of the main dwelling house (AO1.2)
Building height to the zone limit (≈ 9.5 m / 2 storeys in low-density zones)
One additional on-site car parking space
Boundary setbacks and site cover are set by the Queensland Development Code, not the planning scheme

Accepted development vs a development application

If your secondary dwelling meets every Acceptable Outcome of the Dwelling House Code, it's accepted development — you can build under a building approval without a town-planning DA. If it exceeds 80 m², sits more than 20 m from the house, or the site is in a Traditional building character or Heritage overlay (common in Brisbane's older suburbs), it becomes assessable development and needs a DA, where only the outcomes you don't meet have to be justified.

One thing a secondary dwelling can never be: separately sold off. A dwelling house plus its secondary dwelling must remain on a single lot — you can't subdivide to put the granny flat on its own title.

Check your plans against the rules — free

Already have a sketch or plans? Our free Brisbane plan compliance check reads the dimensions straight off your PDF and tests them against the Dwelling House Code Acceptable Outcomes — GFA, height, parking, setbacks — and tells you whether it's accepted development or needs a DA. No login, no charge.

No plans yet? Start with the free Property Snapshot to see your zone and overlays, or the $39 planning report for a plain-English read on exactly what your property allows.

Real example

Worked example

A 75 m² detached secondary dwelling, 12 m behind a low-density-zone house with one extra car space, meets AO1.1, AO1.2 and the parking AO — accepted development, no planning DA. Push it to 95 m² or add it to a character-overlay lot and it tips into assessable development requiring a development application.

The statutory basis

Secondary dwellings in Brisbane are assessed under the Brisbane City Plan 2014 Dwelling House Code (section 9.3.7), made under the Planning Act 2016. 'Secondary dwelling' is a defined use in the Planning Regulation 2017. The 80 m² / 20 m figures are the code's Acceptable Outcomes; a neighbourhood plan or overlay can vary them, so always confirm the controls for your specific address.

Brisbane City Plan 2014 — Dwelling House Code

Section 9.3.7 (AO1.1, AO1.2)

Planning Act 2016 (Qld)

Categories of development & assessment

Planning Regulation 2017 (Qld)

Definition — secondary dwelling

Frequently asked questions

How big can a granny flat be in Brisbane?

Up to 80 m² gross floor area to be accepted development under the Dwelling House Code (AO1.2). Larger is possible but makes the proposal assessable — it needs a development application that justifies the extra size against the performance outcomes.

Do I need council approval for a granny flat in Brisbane?

If it meets every Acceptable Outcome (≤ 80 m², within 20 m of the house, zone height, one car space, QDC setbacks) it's accepted development — building approval only, no planning DA. Outside those limits, or in a character/heritage overlay, you need a development application.

Can I rent out a granny flat in Brisbane?

Yes — a secondary dwelling can be occupied by a separate household, including a tenant. It just can't be on its own title; the main house and secondary dwelling stay on one lot.

Does the granny flat have to be attached to the house?

No. It can be attached or detached, but it must be within 20 m of the main dwelling house to meet AO1.2.

What if my property is in a character overlay?

Brisbane's Traditional building character overlay makes building work (especially to or near a pre-1947 house) assessable development, so a granny flat there generally needs a DA even if the size and siting are within the AOs. The free plan check flags this.

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