Short answer: usually yes. In Brisbane, a secondary dwelling (the report term is granny flat) is treated as part of the dwelling house use, not a separate use needing its own development application, in the Low density residential and Low-medium density residential zones, provided the design meets the Dwelling house code's requirements; other zones are read on their own tables of assessment, per parcel. That "provided" is doing real work: the code sets a numeric test almost everyone checks (floor area and distance from the house) and a qualitative test far fewer people check (whether the design genuinely reads as subordinate to the house), and Brisbane has refused a secondary dwelling application outright on subordination, amenity and definitional grounds after the design missed the numeric test and dropped to code assessment.
What the accepted pathway actually requires
Under Brisbane City Plan 2014's Dwelling house code (9.3.7), a secondary dwelling is accepted development, no material change of use application, subject to compliance with these identified requirements (a building approval is still required regardless):
| Requirement | Standard | Code reference |
|---|---|---|
| Maximum gross floor area | 80 m² | AO1.2 |
| Distance from the dwelling house | Within 20 m | AO1.2 |
| Households | No more than 1 | AO1.1 |
| Car parking | 1 additional space (on top of the house's own space) | AO4 |
The scheme's own words (Dwelling house code 9.3.7.3, Acceptable outcome AO1.2, verified against the operative v36.00/2026 text):
"Any development for a secondary dwelling is: a maximum of 80m2 in gross floor area; located within 20m of the dwelling house."
These are not the whole test. Clearing the 80 m² and 20 m figures gets a design onto the accepted pathway only if it also satisfies the code's qualitative outcomes, which is where owners most often come unstuck.
The subordination test, the condition most owners miss
Alongside the floor-area and distance tests, the Dwelling house code carries a performance outcome that a building other than the dwelling house is used for a domestic residential purpose in conjunction with and is subordinate to the dwelling house, is smaller in size and scale, and has the appearance of a building ancillary to the dwelling house. In plain terms: the secondary dwelling has to look and function like a subordinate structure attached to the household, not a second, independent home that happens to share a title.
This is not a formality. In the Zillmere area, an oversized secondary dwelling proposal, 288 m² against the 80 m² acceptable outcome, missed the numeric test, dropped to code assessment, and was then refused outright with no conditions offered. The recorded refusal reasons were subordinance to the main dwelling, residential amenity, and a finding that the proposal did not meet the scheme's own definition of a secondary dwelling. The lesson is not that granny flats are risky in Brisbane. It is that the code-assessment fallback after a missed acceptable outcome is a live refusal risk, not a routine formality, and that subordination reaches beyond the acceptable-outcome cascade: it sits in the Secondary dwelling definition itself (Schedule 1.2) and in the code's performance and overall outcomes, so a design that is not genuinely subordinate fails to be a secondary dwelling at all.
Where this pathway applies, and where the character overlay adds a step
The firm ground here is the Low density residential and Low-medium density residential zones: in both, the zone's Table of Assessment lists a dwelling house, which carries the secondary dwelling within it, as accepted development. Other zones, including Rural residential, are read per parcel on their own tables of assessment rather than assumed. One wrinkle sits inside the residential zone tables themselves: both carry the same note that the Dwelling house character overlay applies to all land in the zone, which means a dwelling house (and the secondary dwelling within it) can become assessable against the Dwelling house code or the Dwelling house (small lot) code, rather than sitting entirely outside any benchmark check. In practice this does not usually change the outcome for a compliant secondary dwelling, but it means the character overlay is a real input into the design, not paperwork to skip in a character-mapped street.
What flood-mapped land means for a secondary dwelling
Brisbane's flood overlay does not work on a simple risk-tier ladder. Under Table 5.10.11, the Flood overlay's table of assessment (which routes to the Flood overlay code's benchmarks), a new dwelling house, which includes a secondary dwelling built within that use, stays on the accepted pathway even in the highest-risk flood sub-categories (Brisbane River, waterway or overland flow), where a dwelling house is accepted in the zone and the design meets every acceptable outcome in section A of the Flood overlay code. Missing even one of those acceptable outcomes moves the assessment to code assessment, not impact assessment. So flood mapping on a parcel is not, by itself, a reason a secondary dwelling cannot proceed; it is a design-compliance question, confirmed against the mapped flood layer for the specific site and floor design, not assumed from the flood category alone.
Granny flat or dual occupancy: not the same product
A secondary dwelling and a dual occupancy (duplex) answer different questions, and Brisbane gates them very differently. A granny flat stays on one title with the house; it is not separately saleable, a distinction worth confirming before anyone plans around selling it later. A dual occupancy is built to be two separately marketable dwellings under a building format title, and its pathway depends heavily on zone and precinct: in Low-medium density residential it is code assessable where the design stays within the zone table's height and precinct tests, up to 3 storeys and 11.5 m in the applicable precincts (the 3-storey height in the 2 or 3 storey mix precinct also needs a road reserve of at least 15.5 m and part of the site within 400 m walking distance of a rail or busway station), with the Dual occupancy code's own 600 m² site and 15 m frontage figures applying as design benchmarks inside that assessment; in the Character residential zone it is code assessable only in the Infill housing precinct, and only where any house built in 1946 or earlier is retained and the new building stays within 2 storeys and 9.5 m. In Low density residential, dual occupancy is not listed as a use at all, defaulting it to impact assessment, and the LDR zone code states its own intent directly. The scheme's own words, Low density residential zone code 6.2.1.1 (verified 3 July 2026):
"Development maintains a low density character in which multiple dwellings are not accommodated."
For most Low density residential blocks, that is exactly why the secondary dwelling pathway, not dual occupancy, is the one the zone is built for.
How to check your own block
- Find your parcel on Brisbane's City Plan eplan and confirm the zone. Low density residential and Low-medium density residential carry the accepted secondary dwelling pathway; other zones, including Rural residential, are read per parcel on their own Table of Assessment.
- Check the design against the 80 m² floor area, 20 m distance, single-household and parking tests, then, separately, whether the design genuinely reads as subordinate to the house in scale and appearance, not a second independent dwelling.
- Check whether the Dwelling House Character overlay or any other overlay, including flood, applies to the parcel, and confirm which acceptable outcomes it adds for your specific design.
- If the goal is two separately saleable dwellings rather than one subordinate dwelling, check the dual occupancy pathway for your zone and precinct instead; the two products are not interchangeable.
This page is general information about the Brisbane City Plan 2014, not advice about your property. Overlay effects vary lot by lot, planning schemes amend, and the council's current scheme prevails. Do not rely on this page for a specific property. Get a site-specific report or independent professional advice before acting. We work with town planners, not in place of them: where a pathway depends on design or professional judgement, a town planner or the relevant qualified professional confirms it for your specific proposal.
Want the answer for your block? Our $690 site-specific report reads the zone, every overlay mapped on the property and the surviving development pathways for one property, with every figure cited to the scheme. Not ready for that? Start with the free development risk checklist, read our Brisbane planning and zoning guide, or see how the numbers change for a full block split in Can I Subdivide My Land in Brisbane?
Sources: Brisbane City Plan 2014 (the council's official eplan), including the Dwelling house code (9.3.7), the Dual Occupancy code (9.3.6), the Low density residential zone code (6.2.1.1) and Table of Assessment, the Low-medium density residential Table of Assessment, and the Flood overlay code (Table 5.10.11), plus Brisbane City Council's dual occupancy guidance page. Everything on this page comes from the council's own published planning scheme; we explain it in plain English. The scheme text itself is the authority.
Published by LandIntel. How we research: our methodology.
Verified 3 to 10 July 2026 against Brisbane City Plan 2014, version 36.00/2026 (effective 12 June 2026); schemes amend, and the live scheme prevails.