For a dual occupancy, the maximum site coverage is generally 45% of the original block area in RZ1 and RZ2, and 50% in RZ3, RZ4 and RZ5.

There is no separate maximum floor area specified for each individual dwelling. Instead, the size of the two dwellings is determined by the overall site coverage and other requirements such as setbacks, building height, private open space and landscaping.

Reference: Territory Plan 2023 (NI2023-540), Residential Zones Policy, Assessment Requirements 8 (Site Coverage) – Territory Plan 2023 | Notifiable instruments

Yes. Both dwellings in a dual occupancy can share a driveway, provided the driveway, parking and vehicle-access arrangement meets the applicable planning requirements.

The Missing Middle Housing Design Guide specifically recognises dual occupancy as multi-occupancy housing and refers to common landscaping where there is a shared driveway.

Under the Residential Zones Technical Specifications, the driveway and parking arrangement must also address requirements including:

• Required car parking: the required number of parking spaces must be provided for the dwellings.
• Parking location: parking must comply with the rules about where spaces can be located on the block.
• Tandem parking: spaces can be in tandem only where they belong to the same dwelling. This is important—a shared driveway does not mean one dwelling's required parking space can be trapped behind the other dwelling's parking space.
• Property boundaries: parking spaces must not encroach across property boundaries.
• Safe driveway design: Specification 27.4 requires verge crossings and internal driveways to be designed for safe use by pedestrians, cyclists and vehicles, including consideration of vehicle-speed reduction measures.
• Garage/carport presentation: where garages or carports face a street, their openings are also subject to applicable streetscape controls.

The overall arrangement must therefore provide compliant vehicle access, parking and safe movement, even though the physical driveway itself may be shared.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – https://www.legislation.act.gov.au/View/ni/2026-303/current/PDF/2026-303.PDF & ACT Missing Middle Housing Design Guide – 3.1B Multi-Occupancy – ACT Missing Middle Housing Design Guide

No. You do not need to split your land into separate blocks to create a dual occupancy. You can build the two dwellings first and, if eligible, create separate unit titles so each dwelling can be owned or sold separately.

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

Yes, potentially. The ACT Missing Middle Housing Design Guide specifically illustrates dual occupancy development where the existing dwelling is retained and a second dwelling is added. The completed development must still comply with the applicable Residential Zones Policy requirements, including site coverage, setbacks, private open space, planting, parking and access.

Reference: Planning (Missing Middle Housing) Design Guide 2026 – ACT Missing Middle Housing Design Guide & Territory Plan 2023 – Part E01 Residential Zone Policy –  Territory Plan 2023 | Notifiable instruments

Yes. Parking spaces can be arranged in tandem for a dual occupancy, but the tandem spaces must belong to the same dwelling.

This means one dwelling can have two cars parked one behind the other, but a parking space belonging to one dwelling cannot be used in tandem with a parking space belonging to the other dwelling.

Parking must also:

• stay within the property boundaries;
• generally not be located in the front zone, subject to specified exceptions;
• be at least 1.5 m from habitable-room windows or doors of another dwelling; and
• be located within 50 m of the dwelling it serves.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Requirement 27.3, Car Parking – Planning (Residential Zones) Technical Specifications 2026 

Yes, potentially. One dwelling may be occupied while the other is still under construction if the completed dwelling is covered by an appropriate Certificate of Occupancy and Use.

The Building Act 2004 allows a certificate to be issued for a completed part of a building where that part satisfies the applicable requirements. The remaining uncertified part cannot be occupied.

This means it is not automatic that one dwelling can be occupied simply because it is finished—the required occupancy certification must first be obtained.

Reference: Building Act 2004 (2004-11) – Sections 69(3), Certificates of occupancy & 76, Occupation and use of buildings – https://www.legislation.act.gov.au/View/a/2004-11/current/html/2004-11.html

Yes. A dual occupancy must be designed to provide appropriate privacy between the two dwellings and from neighbouring properties.

The current ACT residential requirements address privacy through the location and design of windows, balconies, decks and private open spaces, particularly where they could create direct overlooking. Depending on the layout, the design may need to use measures such as building orientation, separation, privacy screening, fencing, landscaping, louvres or other architectural screening to limit overlooking.

The Missing Middle Housing Design Guide also requires privacy to be considered when locating balconies and private open spaces. These areas should be positioned to minimise overlooking of neighbouring private open spaces, with landscaping, fencing and integrated architectural screening used where appropriate.

The exact privacy treatment required will depend on the position, level and orientation of each dwelling and its relationship to neighbouring properties.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – https://www.legislation.act.gov.au/View/ni/2026-303/current/PDF/2026-303.PDF & Planning (Missing Middle Housing) Design Guide 2026 (NI2026-312) – Section 5.2C Privacy and Outlook –https://www.planning.act.gov.au/__data/assets/pdf_file/0020/3092411/ACT-Missing-Middle-Housing-Design-Guide.pdf?

No, not necessarily. You may be able to retain your existing house and add a second dwelling to create a dual occupancy.

Whether this is possible depends on the existing house's location and whether the completed development can meet the applicable dual occupancy requirements, including site coverage, setbacks, private open space, planting, parking and access.

Reference: Planning (Missing Middle Housing) Design Guide 2026 – ACT Missing Middle Housing Design Guide & Territory Plan 2023 – Part E01 Residential Zone Policy –  Territory Plan 2023 | Notifiable instruments

For a dual occupancy, privacy between the two dwellings should be considered as part of the overall design. The Missing Middle Housing Design Guide provides general guidance for multi-dwelling development on minimising overlooking between dwellings, balconies and private open spaces, including through appropriate siting, landscaping, fencing and screening.

These are design considerations applicable to missing-middle housing generally, rather than privacy rules written specifically for dual occupancy.

Reference: Planning (Missing Middle Housing) Design Guide 2026 – 5.2C Privacy and Outlook – ACT Missing Middle Housing Design Guide

The difference between these residential development types is that a secondary residence is a second dwelling on a block that remains subordinate to the principal dwelling on that block, whereas dual occupancy housing is the use of land that was originally used or leased for single dwelling housing for two dwellings. In contrast, a townhouse development generally consists of multiple dwellings arranged as individual homes within one development site, usually involving a higher density of residential development than a dual occupancy.

Reference: Territory Plan 2023, Part G – Dictionary – Territory Plan 2023 | Notifiable instruments

A secondary residence (granny flat) cannot be sold separately because it is a smaller dwelling that is subordinate to the main dwelling and remains on the same title.

A dual occupancy may be sold separately if the dwellings are separately titled, such as through an approved unit-title subdivision. Simply building a dual occupancy does not automatically mean the dwellings can be sold separately.

Reference:

Territory Plan 2023 – Part E01 Residential Zone Policy, F01 Subdivision Policy –  Territory Plan 2023 | Notifiable instruments

Unit Titles Act 2001(ACT) (A2001-16) (registration and creation of unit titles) – Unit Titles Act 2001

Yes, potentially. You may be able to extend or alter your existing house as part of creating a dual occupancy.

The completed development must provide two dwellings and meet the applicable dual occupancy (multi-unit housing) requirements. This includes requirements such as site coverage, setbacks, building height, private open space, planting, parking and access.

Whether this is possible will depend on the existing house, the block and whether the proposed development can meet the applicable planning and building requirements.

Reference: Planning (Missing Middle Housing) Design Guide 2026 – ACT Missing Middle Housing Design Guide & Territory Plan 2023 – Part E01 Residential Zone Policy –  Territory Plan 2023 | Notifiable instruments

For a dual occupancy, the parking requirements depend on the residential zone and the number of bedrooms in each dwelling.

For RZ1 and RZ2:

• At least 1 car parking space per dwelling.
• Plus 1 additional space for every five 2-bedroom dwellings.
• Plus 1 additional space for every three dwellings with 3 or more bedrooms.

For a typical dual occupancy of only two dwellings, this means the starting requirement is 2 parking spaces in total — one for each dwelling. Additional parking is calculated across the development according to the bedroom-based rates above.

For RZ3, RZ4 and RZ5, the same resident parking rates apply. Visitor parking is additionally required where a development contains 4 or more dwellings, so this visitor-parking requirement would not normally apply to a two-dwelling dual occupancy.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Parking Provision Rates for Residential Zones & Requirement 27.3 Car Parking – https://www.legislation.act.gov.au/View/ni/2026-303/current/PDF/2026-303.PDF

Yes, potentially. The two dwellings in a dual occupancy do not necessarily have to be the same size.

For an RZ1 dual occupancy on a standard block proposed for unit titling, the Subdivision Policy requires one dwelling to have a maximum dwelling size of 120 m². This requirement applies to one dwelling only, so the other dwelling may be larger, subject to all other applicable planning requirements. ACT Planning likewise explains the rule as requiring “one dwelling” to be no more than 120 m².

Reference: ACT Territory Plan, F01 Subdivision Policy – Territory Plan 2023 | Notifiable instruments

Potentially, yes. Dual occupancy may be permitted on land in ACT residential zones where multi-unit housing is permitted, including RZ1 Suburban, RZ2 Suburban Core, RZ3 Urban Residential, RZ4 Medium Density Residential and RZ5 High Density Residential.

Whether you can actually build a dual occupancy on your block will depend on its zoning, Crown lease, site constraints and proposed design. The development must meet the applicable requirements for matters such as site coverage, setbacks, building height, private open space, planting, parking and access.

Reference: Territory Plan 2023 – Part E01 Residential Zone Policy –  Territory Plan 2023 | Notifiable instruments

Yes, potentially. The ACT Missing Middle Housing Design Guide specifically shows dual occupancy developments on corner blocks, including attached and detached layouts that make use of the different street frontages.

Whether each dwelling can face a different street will depend on the particular block and design, including how the development addresses the street frontages, parking access and surrounding streetscape.

Reference: ACT Missing Middle Housing Design Guide – Part 3, Section 3.1B Multi-occupancy – https://www.planning.act.gov.au/__data/assets/pdf_file/0020/3092411/ACT-Missing-Middle-Housing-Design-Guide.pdf?utm_source

No. Building or obtaining approval for a dual occupancy does not automatically mean the two dwellings qualify for separate titles.

Creating separate unit titles involves a unit title subdivision, which must separately comply with the applicable Territory Plan subdivision requirements and the Unit Titles Act 2001.

Whether separate titles can be obtained therefore depends on whether the particular dual occupancy satisfies those requirements.

Reference: Territory Plan 2023 (NI2023-540), Part F1 – Subdivision Policy – https://www.legislation.act.gov.au/ni/2023-540/Current

Yes, potentially. A dual occupancy can be built in a Bushfire Prone Area (BPA), but additional bushfire planning and construction requirements apply.

The ACT Bushfire Management Standards apply to all development within a mapped Bushfire Prone Area, including residential development. The proposal must respond to the site's bushfire risk and incorporate the applicable Bushfire Protection Measures, which may include building separation and defendable space, appropriate emergency access and egress, construction standards, services and vegetation/fuel management.

Being in a Bushfire Prone Area therefore does not automatically prohibit a dual occupancy, but the development must satisfy the applicable bushfire requirements.

Reference Emergencies Bushfire Management Standards 2025 (NI2025-265) – https://www.legislation.act.gov.au/View/ni/2025-265/current/html/2025-265.html

Generally, no. The age of the existing house by itself does not determine whether a dual occupancy can be approved. The application is assessed against the current planning requirements applying to the block and proposed development.

The ACT Missing Middle Housing Design Guide specifically illustrates a detached dual occupancy that retains the existing dwelling, showing that retaining an older/existing house is contemplated.

However, the age of the house may become relevant if it has heritage protection or other site-specific constraints. Heritage requirements can affect alterations, additions, new buildings, demolition, landscaping, site coverage and setbacks.

Reference: ACT Missing Middle Housing Design Guide – ACT Missing Middle Housing Design Guide

Yes, for a unit-titled dual occupancy. Each dwelling must be covered by a Certificate of Occupancy and Use. ACT Planning specifically requires the most recent certificate for each unit before the unit-title application can be approved.

Reference: ACT Planning: Guide to Unit Titling Process – https://www.planning.act.gov.au/community/buy/leasing-and-titles/unit-titles/guide-to-the-unit-title-application-process

Before either dwelling in a dual occupancy can be occupied, it must be covered by a Certificate of Occupancy and Use for its intended residential use. For building work requiring a certifier, the certifier must first issue the required Certificate of Completion. ACT Planning also notes that completion includes relevant electrical, gasfitting and plumbing work.

It is unlawful to occupy or use a building, or part of a building, without the required Certificate of Occupancy and Use.

Reference: Act Planning: Completion Certificates – https://www.planning.act.gov.au/community/build-or-renovate/upon-completion/completion-certificates

A dual occupancy has two dwellings, so you do not need to add another parking space specifically for visitors.

You still need to provide the required parking for the people living in each dwelling. The number of resident spaces depends on the number of bedrooms and the applicable parking requirements.

The separate visitor-parking requirement starts when a residential complex has four or more dwellings.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026–303), Assessment Outcome 27, Table 12 – Planning (Residential Zones) Technical Specifications 2026

• The Territory Plan 2023 determines whether a dual occupancy is permitted on an RZ1 property.

• Under Part E – Zone Policies, E1 Residential Zones Policy, the RZ1 land use table identifies multi-unit housing as a permissible use.

• While the land use table does not specifically refer to "dual occupancy", Part G – Dictionary defines dual occupancy as a form of multi-unit housing.

• Therefore, dual occupancy is considered a permissible form of development in RZ1, subject to compliance with the applicable Territory Plan assessment requirements and approval under the Planning Act 2023 (ACT).

Reference: Territory Plan 2023 – Part E, E1 Residential Zones Policy (Land Use Table) & Part G Dictionary (definitions) – https://www.legislation.act.gov.au/ni/2023-540/Current

Yes. A dual occupancy can be designed on a battle-axe block, subject to meeting the applicable planning requirements.

The ACT Missing Middle Housing Design Guide specifically provides an example of a dual occupancy on a battle-axe block. In the example, the block also fronts public open space, and the dwellings are positioned to provide front gardens and direct access to the public open space, supporting activation and passive surveillance

Whether a particular battle-axe block can accommodate a dual occupancy will still depend on the site's circumstances and compliance with the applicable Territory Plan requirements.

Reference: ACT Missing Middle Housing Design Guide – Site and Land Use → Irregular Blocks – https://www.planning.act.gov.au/__data/assets/pdf_file/0020/3092411/ACT-Missing-Middle-Housing-Design-Guide.pdf