ACT Land Zone RZ1 – You Can Now Build a Dual Occupancy up to 120m and Subdivide Your Block

November 2, 2023

Canberra is witnessing a significant shift in residential planning rules, allowing more landowners to divide their blocks into dual-occupancy housing, ultimately increasing housing options and affordability. The key points of these changes include:

Owners of residential blocks that are 800 square meters or larger will now have the opportunity to split their blocks into dual-occupancy properties. One of the two dwellings will be limited to 120 square meters of floor space, making it more accessible and affordable for potential homeowners. Approximately 45,000 blocks in Canberra may be eligible for this policy change, with a significant concentration in the Tuggeranong and Belconnen districts.

ACT Government Wants More Homes in RZ1

The ACT government's objective is to stimulate the creation of more homes in existing suburbs while enhancing affordability. However, it's important to note that these changes apply only to blocks where secondary dwellings are already permitted.

Under the new Territory Plan, which serves as the central planning document for the ACT, residential zone 1 (RZ1) blocks measuring 800 square meters or more will be eligible for the construction of two homes. According to ABC News, RZ1 blocks are the most prevalent in Canberra, constituting approximately 73% of all zoning types, primarily designed for single, detached houses.

Previously, owners of larger RZ1 blocks could build a secondary residence with a maximum floor space of 90 square meters, but they couldn't subdivide the block into two separate titles for resale. With the new policy, formal subdivision is allowed, with each block obtaining an independent title, and the secondary dwelling's floor space is extended to 120 square meters.

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Additionally, the government has introduced new regulations ensuring that an adequate number of trees are planted on these blocks to contribute to the expansion of Canberra's urban forest.

ACT land data suggests that almost 45,000 blocks meet the eligibility criteria for these changes, primarily concentrated in the Tuggeranong and Belconnen districts. Certain suburbs, including Forrest, O'Malley, Weetangera, and Turner, have a high proportion of RZ1 blocks that are large enough to qualify for the new dual-occupancy rules, offering homeowners an opportunity to make the most of this policy shift.

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FAQ for Land Subdivision in ACT RZ1

What is the  Maximum Size for a Second home on a Dual Occupancy block ?

The maximum size was 90m2 and has been increased to 120m

Is there a minimum size?

Depending on the type of secondary dwelling there may be a minimum size. This is a rough guide for minimum dwelling floor areas:

  1. Studio dwellings - 40m²
  2. One-bedroom dwellings - 50m²
  3. Two-bedroom dwellings - 70m²
  4. Dwellings with 3 or more bedrooms - 95m²

The minimum dwelling floor area excludes balconies and car parking facilities. Storage within dwellings is included in the area calculations.

When does the subdivision occur?

Subdivision is planned for at design and construction stage but occurs after our building work is complete.

Does Cubitt’s include Subdivision in a quote?

Cubitt’s designers and builders will work with you under the assumption that your land will be subdivided after the project is complete, however this work needs to be done by a local surveyor. Cubitt's have trusted contacts we can help you contact during the process.

Can I build a Cubitt's Granny Flat and then Subdivide?

Yes! Cubitt's standard ACT designs are up to 90m2, which is suitable for a dual occupancy. If you want to maximise the 120m2 and your property is suitable you can modify our designs to add more rooms. Download the design collection

What if my land is less than 800m2?

You wont be able to subdivide, but if you have enough space, you could still be eligible for a Granny Flat. Don't hesitate to book a consultation


Cubitt's are committed to making your building project stress free and simple. Responsible for your result, you can be assured that we will be aiming to complete your project with the best outcome for your long term use of the home. Building a home is a journey we are privileged to go on with our clients, and Cubitt's are committed to being completely transparent and delivering the highest standards of communication along the way.

Canberra's Trusted Granny Flat Builders

Choose compact luxury clever living when you build a Granny Flat with Cubitt's 

If you live in the ACT and are searching for a clever way to invest in your own property, a Granny Flat built by Cubitt’s may be exactly what you’re looking for. Our customers are building Granny Flats in Canberra for myriad of reasons. For example, as a comfortable alternative to expensive and overcrowded nursing homes, that keep your elderly loved ones close while maintaining your personal space for daily life. Families are investing in Granny Flats in Canberra to pay off a mortgage much faster by making the most of vacant backyard space. With the ability to build a Granny Flat from 40m2 up to 90m2 in the ACT, the possibilities are endless for you to maximise the return on your property.

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Cubitt's Display Centre

80-82 Kembla Street,
Fyshwick ACT 2609

Opening Hours:
Monday-Saturday: 9am-4pm

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Interested in finding out how to make a positive investment from a Cubitt's Granny Flat or Home Extension? Get in touch for a no-obligation site inspection today.

If you are looking to purchase a new property and want to do a Granny Flat Suitability Check - please use this form instead.

We require your name, email and phone number to get back to you - and the more you can tell us about your build project, the more effectively our local teams can help.


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About Vince Zinghini

Vince is Cubitt's Director of Planning. With two decades experience in NSW and ACT Council planning and a team of people covering the specific areas in which Cubitt's build, its rare to find a planning scenario we haven't been able to tackle.