Do both dwellings in a dual occupancy need to be the same size?
No. The two dwellings in a dual occupancy do not need to be the same size. One dwelling can be larger than the other.
The current ACT planning requirements do not generally require equal dwelling sizes. However, the overall development must comply with the applicable requirements, including site coverage, setbacks, building height, private open space, planting, parking and access. These controls may affect how large each dwelling can be.
Reference: Planning (Missing Middle Housing) Design Guide 2026 – ACT Missing Middle Housing Design
Short Answer
No. The two dwellings in a dual occupancy do not have to be the same size. One can be larger than the other, provided the overall development meets the applicable planning requirements.
Detailed Explanation
No. The ACT Residential Zones Policy does not generally prescribe that the two dwellings comprising a dual occupancy must have equal floor areas.
The dwellings may therefore be designed with different floor areas, provided the development as a whole satisfies the applicable multi-unit housing assessment requirements, including site coverage, setbacks, building height, private open space, planting, parking and access.
The ACT Missing Middle Housing Design Guide provides additional guidance and examples for the design and configuration of dual occupancy developments.
No minimum block size does not remove the need for planning assessment.
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