Dual occupancy rules in Australian Capital Territory (2026)

Yes in most suburban areas, following a major change. The Missing Middle Housing reforms commenced on 1 July 2026 and allow duplexes, triplexes, terraces and townhouses of up to two storeys in RZ1 and up to three storeys in RZ2, removing the previous 800 m² minimum block size for a second dwelling in RZ1.

Depends on your lot

Now allowed in RZ1 and RZ2 after the 2026 Missing Middle reforms

Approval pathway: A development application to the ACT Planning Authority is required, assessed in the merit track against the Territory Plan 2023, the residential zones development code and the Missing Middle Housing Design Guide. Because ACT land is leasehold, adding dwellings or unit titling normally also requires a lease variation - and a 50 percent reduction in the codified lease variation charge applies to eligible missing middle developments until June 2029.

Key rules at a glance

Minimum block size	The former 800 m² minimum for a second dwelling in RZ1 was removed on 1 July 2026. What now limits capacity is site coverage, setbacks, canopy cover and design outcomes (indicative - confirm the current Territory Plan rules for your block).
Zones permitted	RZ1 Suburban and RZ2 Suburban Core, plus the higher density residential zones. RZ1 is capped at two storeys; RZ2 allows up to three.
Second dwelling size	No size cap. Under the Territory Plan 2023 a second dwelling in RZ1 had to be 120 m² or less (excluding the garage) to be unit titled; that cap was removed by the Missing Middle reforms on 1 July 2026. Site coverage, setbacks, canopy cover and design outcomes now govern
Approval pathway	Merit track development application to the ACT Planning Authority, usually accompanied by a lease variation.
Can it be subdivided or unit titled?	Yes. Unit titling and block subdivision are permitted in both RZ1 and RZ2, so two dwellings can be separately titled and sold. Since 1 July 2026 unit titling is available on blocks above 600 m² (previously 800 m²)
Typical timeframe	Commonly 3-6 months for a merit track development application, longer where a lease variation is involved.

Conditions & eligibility

All ACT land is leasehold - your Crown lease purpose clause must allow the number of dwellings proposed, or be varied.
Site coverage, plot ratio, setbacks and canopy cover requirements in the residential zones development code apply.
Development in RZ1 is capped at two storeys; RZ2 allows up to three.
The Missing Middle Housing Design Guide sets the design expectations the application is assessed against.
Heritage-listed properties and precincts, and blocks affected by bushfire or flooding, face additional assessment.
A lease variation charge applies to added dwellings, halved for eligible missing middle developments until June 2029.

Overlays can change your eligibility

Heritage, flood and bushfire controls on your specific lot can remove the fast-track and require a full application — even when the general rules say you're fine.

HeritageFloodBushfire

Check your address for overlays →

How approval works in Australian Capital Territory

A development application to the ACT Planning Authority is required, assessed in the merit track against the Territory Plan 2023, the residential zones development code and the Missing Middle Housing Design Guide. Because ACT land is leasehold, adding dwellings or unit titling normally also requires a lease variation - and a 50 percent reduction in the codified lease variation charge applies to eligible missing middle developments until June 2029.

The ACT has no councils - the ACT Planning Authority assesses every development application territory-wide, though precinct codes and heritage precincts still create local variation.

Dual occupancy rules by council in Australian Capital Territory

Local councils apply the Australian Capital Territory framework and can add their own controls. Pick your council:

Canberra

Frequently asked questions

Can I build a duplex on an RZ1 block in Canberra?

Yes, since 1 July 2026. The Missing Middle Housing reforms allow duplexes, triplexes, terraces and townhouses of up to two storeys in RZ1, and the previous 800 m² minimum block size for a second dwelling has been removed. You still need a merit track development application, and site coverage, setbacks and canopy cover requirements decide how much actually fits.

Can the two dwellings on an ACT block be sold separately?

Yes. Unit titling and block subdivision are permitted in RZ1 and RZ2 under the 2026 reforms. Before then, unit titling an RZ1 dual occupancy required a block of at least 800 m² with one dwelling no larger than 120 m² excluding the garage - which is why many older Canberra dual occupancies could never be split and sold.

Do I need a DA for a second dwelling in Canberra?

Yes. A merit track development application to the ACT Planning Authority is required, assessed against the Territory Plan 2023 and the Missing Middle Housing Design Guide. Because ACT land is leasehold you will usually also need a lease variation, which attracts a lease variation charge - halved for eligible missing middle projects until June 2029.

Sources

Last reviewed: July 2026. Rules can change — verify with your council before starting work.

Related building rules

This is general guidance, not professional planning advice. Figures are summarised from the sources above and can change — confirm with your council or the ACT Planning before starting work. Last reviewed: July 2026.

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