Your block has a zone, such as a residential zone, which sets the main planning framework for what can be developed. An overlay is an extra layer on top of that zone. It identifies an area where something additional needs to be considered when developing the land.

For a dual occupancy, this means you need to check both the residential zone requirements and any overlay applying to the block.

Having an overlay does not automatically mean a dual occupancy cannot be approved. What matters is which overlay applies and what requirements it introduces.

Reference: Planning Act 2023 (A2023-18) – https://www.legislation.act.gov.au/View/a/2023-18/current/html/2023-18.html

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 parking for each dwelling does not necessarily need to be directly beside or in front of that dwelling.

Parking for a rear dwelling may be located further into the block, including behind the front dwelling. The layout will need to provide suitable vehicle access and meet the required parking dimensions and manoeuvring requirements.

If one vehicle has to park behind another vehicle, this becomes a tandem parking arrangement, which needs to be considered separately.

Reference : Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) — Assessment Outcome 27 (Parking) – Planning (Residential Zones) Technical Specifications 2026

Having a window facing a neighbour does not automatically mean there is an overlooking problem.

The main concern is whether someone can easily look from the new dwelling into areas where a neighbour would normally expect privacy, particularly their private open space or habitable rooms.

Depending on the layout, privacy can often be addressed through the position and height of windows, obscure glazing, screening, sill heights, or changing the orientation of balconies and windows.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Planning (Residential Zones) Technical Specifications 2026 

If both dwellings remain on the same lease, sharing or crossing services does not automatically mean a new easement is required.

It becomes more important if the dwellings are intended to have separate titles or separate areas of ownership. For example, if the sewer, water, stormwater, electricity or telecommunications serving one dwelling needs to run through the other dwelling's land, an easement may be needed to protect access to that service for future maintenance.

For a dual occupancy, we would therefore check the hydraulic and utility servicing plans together with the proposed titling arrangement before confirming whether an easement is necessary.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 29 Servicing and Infrastructure – Planning (Residential Zones) Technical Specifications 2026 

Older houses were often built under different planning rules, so they may have setbacks, site coverage or other features that would not meet today’s requirements.

That does not automatically mean the existing house has to be changed or demolished.

If you want to develop the property further, we would first check whether the existing house was lawfully established and then assess how it affects the new proposal. For example, an existing house may take up a large part of the block, leaving less room to meet current requirements for site coverage, private open space, planting, parking, setbacks or separation.

In some cases, the new development may need to be redesigned—or alterations to the existing house may be required—to achieve an acceptable overall development.

Reference: Planning Act 2023 (A2023-18) – Planning Act 2023

Planning requirements can vary from one block to another across the ACT.

For your block, we would check its residential zone, the relevant District Policy, any overlays or site-specific provisions, and the requirements that apply to the type of development you are proposing.

For a dual occupancy, these checks help determine requirements such as building height, setbacks, site coverage, parking, private open space, solar access and other design requirements.

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

If there is an existing structure on the block that does not have the necessary approvals, it should be identified before preparing the new development application.

For example, an unapproved extension, garage, carport or other structure may take up space needed for the new development or affect requirements such as setbacks, site coverage, private open space, planting or parking.

It does not necessarily mean a new DA cannot proceed, but the unapproved structure may need to be dealt with separately or incorporated into the overall development strategy.

Reference: Building Act 2004 (ACT), current version — including s 69(2B); Certificate of completion of unsubstantiated building work – https://www.legislation.act.gov.au/View/a/2004-11/current/html/2004-11.html

You do not necessarily need to pay for a complete set of detailed plans before finding out whether your development idea is realistic.

An early assessment can check things such as the property’s zoning, Crown lease, block size, applicable planning requirements, easements, heritage or environmental constraints, and other site conditions. This can help identify major issues before significant money is spent on detailed design.

Concept plans may then be prepared once there is a clearer understanding of what is likely to work on the

Reference: ACT Planning – Before you apply – Before you apply – City and Environment Directorate – Planning

A sloping block can still be developed, but the slope may affect where and how the building can sit on the land.

For example, a steep slope may require more excavation or retaining walls, and parts of the building may sit higher above the existing ground. This can affect building height, driveway access and the relationship of the development to neighbouring properties.

We would normally review the site levels and survey information early in the design process so the development can work with the slope rather than relying on significant changes to the land.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Planning (Residential Zones) Technical Specifications 2026

A corner block can give you more ways to arrange a development because there are two street frontages to work with.

For example, it may be possible to orient the dwellings toward different streets or consider different locations for entrances and driveways. This can be useful when designing a dual occupancy.

However, both street frontages need to be considered in the design. Setbacks, driveway locations, pedestrian access and the way the development presents to each street can reduce some of that flexibility.

The actual development potential therefore depends on the block dimensions, zoning, street layout and applicable planning requirements, not simply on the property being a corner block.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Planning (Residential Zones) Technical Specifications 2026

The second storey may need to be set further back from a boundary than the ground floor.

This helps reduce the apparent bulk of a two-storey building and provides greater separation from neighbouring properties. It can also assist with privacy and solar access.

So, even where the ground floor can be relatively close to a boundary, the upper floor may need to step back further.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 14 Height, Bulk and Scale – Planning (Residential Zones) Technical Specifications 2026 

A new development should not be designed without considering what is around it.

The position, height and size of neighbouring buildings can influence where the new dwellings, windows and outdoor areas are best located. The design should also consider privacy, overshadowing and how the new buildings sit alongside neighbouring homes.

This does not mean the development has to copy the houses next door. It means the design should respond appropriately to the site and its surroundings.

Reference: Planning (Missing Middle Housing) Design Guide 2026 (NI2026-312) – ACT Missing Middle Housing Design Guide

A new development does not have to look exactly like the houses next door.

What matters is how well it fits into its surroundings. Things such as the size and scale of the building, its position on the block, how it presents to the street, and its relationship with neighbouring properties can all be relevant.

For example, a contemporary dual occupancy may still be appropriate in an area of older houses if its overall scale, siting and streetscape response are suitable.

Importantly, planning considers the desired character of an area, which may be different from what is currently built there.

Reference: Territory Plan 2023 – Part E, E01 Residential Zones Policy – Territory Plan 2023 | Notifiable instruments

There is no general rule saying that a block must be rectangular. However, its shape can influence where and how much you can build.

For example, on a triangular or irregular block, the side boundaries may converge toward the rear. Once the required setbacks are applied, the resulting buildable area may become narrower, which can affect the size, position and layout of the proposed dwelling.

Similarly, a narrow block may make it more difficult to accommodate a driveway, parking, planting and private open space while still meeting the required building setbacks.

The important point is that block shape itself is not necessarily a restriction; it is how that shape interacts with the applicable planning controls that determines the development potential.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-30) – Planning (Residential Zones) Technical Specifications 2026 | PDF

An unusual block shape does not automatically prevent development. What matters is whether a compliant and functional development can be designed within the actual boundaries of the block.

For example, a triangular block may become very narrow toward the rear. Once the required side and rear setbacks are applied, there may be less usable space for a building than on a rectangular block of the same overall area.

The design may therefore need to be adjusted to suit the site's shape.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Planning (Residential Zones) Technical Specifications 2026 | PDF

Your Crown lease sets out how the land is allowed to be used. ACT Planning confirms that leased land and buildings can only be used for a purpose authorised by the lease.

If what you want to build is not permitted by the lease, there are generally two options: change the proposal so that it complies with the existing lease, or seek approval to vary the Crown lease

If the project includes both the physical development and the necessary lease variation, ACT Planning states that they can be included in one DA.

Reference: ACT Planning Changes to Crown Lease – https://www.planning.act.gov.au/community/buy/leasing-and-titles/crown-leases/changes-to-a-crown-lease

If your proposed development also requires the Crown lease to be changed, the development and lease variation can form part of the same DA rather than lodging two separate DAs.

Reference: ACT Planning Changes to a Crown Lease – https://www.planning.act.gov.au/community/buy/leasing-and-titles/crown-leases/changes-to-a-crown-lease

The purpose clause is not necessarily fixed forever. If it does not allow what you want to do with the property, you can apply to have it changed.

For example, if the existing purpose clause only permits a particular residential use and you want to introduce another use, you may apply through a Development Application (DA) to vary the Crown lease. ACT Planning will assess whether the proposed new purpose is appropriate under the Territory Plan

Reference: ACT Planning Changes to a Crown Lease – https://www.planning.act.gov.au/community/buy/leasing-and-titles/crown-leases/changes-to-a-crown-lease

Think of the Territory Plan as establishing what planning rules potentially allow for the area, while the Crown lease can place additional restrictions on the particular property.

For example, the Territory Plan might allow multi-unit housing on a block, but the Crown lease may contain wording limiting the block to one dwelling. In that situation, the Territory Plan allowance does not automatically remove the one-dwelling restriction in the Crown lease. The lease may need to be varied before the additional dwelling can proceed.

Reference: ACT Planning, Advisory Note 11 – Working out Crown lease maximum number of dwellings, particularly the examples of residential Crown lease purpose clauses limiting dwelling numbers –

An Assessment Outcome focuses on the result, rather than prescribing only one design solution. Technical Specifications provide more detailed information—such as dimensions, percentages, distances or other metrics—that can help demonstrate that result.

Example: An Assessment Outcome may require development to provide appropriate privacy between dwellings. The Residential Zones Technical Specifications may then provide measurable solutions relating to matters such as separation or overlooking that can be used to demonstrate that the privacy outcome is achieved.

A proposal does not necessarily have to follow a Technical Specification exactly if another design solution can satisfactorily demonstrate the applicable Assessment Outcome. However, Assessment Requirements are different again—they are mandatory and must be met.

Reference: ACT Planning, Advisory Note 06 – Planning Technical Specifications – Planning Technical Specifications

No. Adding fill or changing the ground around the building does not give you extra allowable building height. The building height is measured from the established Datum Ground Level, which provides the baseline for height calculations.

DGL is established by a registered surveyor based on the ground level at the relevant historical point, such as subdivision or the first lease. If that information is unavailable, the surveyor determines the best estimate of the original surface level using the surrounding ground levels and available information.

Example: If you add 500 mm of fill around a proposed house, you cannot simply measure the building from the top of that new fill to gain an additional 500 mm of allowable height.

Reference: ACT Planning, Advisory Note 09 – Building Heights, Storeys and Basements – Building heights, storeys and basements

If previous building work, excavation or filling has changed the ground, the current ground level is not automatically treated as the original or natural ground level.

A registered surveyor first looks for reliable information showing the ground level from when the subdivision received Operational Acceptance, or, where applicable, from when the first lease was granted before later earthworks occurred.

If that information is unavailable, the surveyor determines a best estimate of the original ground surface. This involves looking at the levels of the immediate surrounding area and identifying areas that have previously been disturbed.

Example: If a previous owner raised part of the backyard with fill, the top of that fill does not automatically become the DGL. The surveyor may reconstruct the likely original ground profile using surrounding undisturbed levels and other available survey evidence.

Reference: Guideline No 3 – Estate Development Plans & Datum Ground Level Surveys – https://www.planning.act.gov.au/__data/assets/pdf_file/0007/2572459/surveyor-general-guideline-03-estate-development-plans-datum-ground-level-surveys.pdf

No. A retaining wall is generally assessed separately from the house, so it is not added to the house when measuring the house's setback or height.

For example, if a retaining wall is closer to the side boundary than the house, you would not normally use the retaining wall as the outer edge of the house and say that the house itself breaches its side setback. The house setback is assessed from the relevant part of the building.

The retaining wall still needs to be checked separately because different requirements may apply to the wall depending on its height and where it is located.

Similarly, the height of a retaining wall is not added to the building height simply because the house is located behind or above it.

Reference: ACT Planning Advisory Note 09 – Building Heights, Storeys and Basements – Building heights, storeys and basements

You generally cannot choose whichever planning requirement is easier to satisfy.

First, check the wording carefully. Two requirements that initially appear to conflict may actually apply to different development types, zones, parts of a block or circumstances.

If they genuinely conflict and come from different parts of the Territory Plan, check the Territory Plan hierarchy to determine which has priority.

If both requirements are in the same policy, the hierarchy does not make one more important than the other. Both should be addressed where they apply.

Example: If two requirements within the Residential Zones Policy appear to give different requirements for a dual occupancy, first check whether one applies only to a particular zone or type of development. If both are applicable mandatory Assessment Requirements, the design needs to satisfy both rather than selecting one over the other.

Reference: Territory Plan – Part A: Administration and Governance – Hierarchy of Territory Plan components