Questions & Answers

Is there a maximum size for the second dwelling?

Yes. If the second dwelling is a secondary residence (granny flat), it can be a maximum of 90 m², excluding the garage.

For a dual occupancy, different rules apply. In RZ1, the applicable requirements depend on the block and proposal, so the 90 m² secondary-residence limit should not be applied to a dual occupancy.

Reference: Territory Plan 2023 – Part E, E1 Residential Zones Policy (Secondary Residence) – https://www.legislation.act.gov.au/ni/2023-540/Current

Last reviewed: 14 September 2026 Information current as at: 16 September 2026

Short Answer

Secondary residence / granny flat: Maximum 90 m², excluding the garage.

Detailed Explanation

Under the ACT Territory Plan Residential Zones Policy, the maximum dwelling size of a secondary residence is 90 m². For this requirement, dwelling size is measured to the outside face of the external walls and includes internal walls between living areas and the garage, but excludes the garage. A maximum of one secondary residence is permitted per block.

A dual occupancy is subject to different provisions and should not be assessed using the 90 m² secondary-residence limit. The applicable dwelling-size, site-coverage and other development controls depend on the zone, block and particular form of dual-occupancy development.

Key Point

No minimum block size does not remove the need for planning assessment.

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