A granny flat design that fits a backyard is not automatically allowed on that block. In 2026, Australia has no single council rule for secondary dwellings: the state or territory framework, your council's planning controls, the site's constraints and building approval all matter. Check your address with the relevant authority before purchasing a design.
- Granny flat designs are not pre-approved for every Australian council or property.
- Victoria generally allows small second homes up to 60 m² without a planning permit, but a building permit is required.
- Queensland allows secondary dwellings to be rented to anyone, but local approval and building requirements still apply.
- Check your exact lot, setbacks, hazards and approval pathway before buying a granny flat floor plan.
Australian House Design Group offers granny flat designs for comparing layouts, not a substitute for a property-specific approval check. The same drawing can be suitable for consideration on one site and need alteration or a different approval pathway on another. This guide summarises the position in September 2026, not every council's rules or a determination for your land.
Why local granny flat regulations matter
A secondary dwelling is generally a smaller home associated with an existing main home, but the official name and tests vary. A granny flat is not necessarily the same planning use as a duplex, independent unit, movable dwelling or holiday accommodation. Getting the classification wrong can change the approval route, design standards and whether your intended use is allowed.
A council can apply its local planning scheme, site overlays and assessment rules within the state or territory framework. A building certifier or surveyor also checks construction requirements. A planning-permit exemption does not mean permission to build without a building permit; a small floor area does not guarantee approval. Ask about the specific property, not just a suburb or a council-wide summary.
Granny flat regulations by state and territory in 2026
| Jurisdiction | What to check first | Why a design still needs a site check |
|---|---|---|
| New South Wales | Housing SEPP and the NSW Planning Portal's secondary-dwelling pathway | Zoning, development standards and bushfire constraints can change the approval route. |
| Victoria | Small second dwelling rules, lot size and planning overlays | A 60 m² design may still require a planning permit in some circumstances; a building permit is required. |
| Queensland | Council planning scheme and building approval | Statewide rental occupancy changes did not remove local development or building approvals. |
| Western Australia | R-Codes, local planning framework and building permit | The 70 m² R-Code figure is not a universal permission for every lot. |
| South Australia | Address-based Planning and Design Code assessment | Ancillary accommodation needs approval; zone and overlay controls affect siting. |
| Tasmania | Current Tasmanian Planning Scheme and local provisions | A proposed increase from 60 m² to 90 m² must not be mistaken for an operative rule. |
| Australian Capital Territory | Territory Plan and secondary-residence approval process | Lease, block and building requirements need assessment by ACT authorities. |
| Northern Territory | NT Planning Scheme zone and independent-unit rules | The relevant zone, services and building certification affect the proposal. |
These figures describe particular legal definitions, not maximum dimensions for every granny flat design sold online. Confirm how floor area is measured and whether decks, garages or other spaces count in your jurisdiction before comparing a plan to a limit.
New South Wales: a state framework, with site-specific limits
The NSW Department of Planning's secondary dwelling guidance says granny flats are allowed in designated residential zones under the Housing SEPP, and some councils also allow them in other zones. A development application or complying-development route may be available depending on the proposal. The Housing SEPP's development standards still apply, and a secondary dwelling approved under its conditions cannot be separately subdivided.
For a NSW property, identify the land's zone and any mapped hazards before picking a plan. The department says some bushfire-prone land cannot use the complying-development route. Ask your council or a qualified certifier whether your block qualifies, which setbacks and floor-area rules apply, and what additional certificates are needed. Do not interpret a catalogue label such as 'granny flat' as confirmation that a design qualifies for a complying-development certificate.
Victoria: 60 m² does not eliminate all approvals
Victoria's small second homes guidance defines a small second home as a dwelling of 60 m² or less on the same lot as an existing home, with a kitchen, bathroom and toilet. In most cases it does not need a planning permit where there are no special controls such as flooding or environmental overlays. It always needs a building permit and cannot be separately subdivided and sold.
The detail matters in 2026: the Victorian guidance also says a small second dwelling on a residential-zone lot under 300 m² generally requires a planning permit under clause 54, apart from the stated Low Density Residential Zone exception to that clause's operation. Your local planning scheme and overlays remain relevant. Confirm lot size, zone, garden-area and siting rules with the council or building surveyor before relying on a 60 m² floor plan.
Queensland: renting permission is not building permission
The Queensland Government's secondary-dwelling guidance says the statewide change permits secondary dwellings to be rented to people unrelated to the main household. That change did not remove development, building or fire-safety requirements. New secondary dwellings need building approval; council determines whether development approval is required for the property.
A concrete council example is the City of Gold Coast dwelling guidance: a secondary dwelling in a residential zone often does not need a development application if it meets the secondary-dwelling code and other applicable codes, but building approval is still needed. Setback departures can bring the council into the assessment. This is Gold Coast guidance, not a rule for Brisbane, Sunshine Coast or every Queensland block. If you intend to rent the dwelling, ask a certifier about any additional fire and sound requirements.
Western Australia: check the R-Codes and the local scheme
The WA Residential Design Codes Volume 1, April 2026 lists a 70 m² maximum internal floor area for an ancillary dwelling associated with a single house or grouped dwelling in its specified assessment table. Other controls, including site cover, setbacks and the relationship to the main dwelling, also apply. Local planning frameworks and site-specific constraints must be checked before you treat that number as an approval.
For a local illustration, the Shire of Coolgardie's planning FAQs discuss residential-zone site requirements and say converting or relocating a structure as an ancillary dwelling requires development approval. A plan that meets a floor-area figure alone does not settle whether it can be built on a particular WA lot. Ask the relevant local government and building permit authority about the current pathway.
South Australia: use the address-based code
South Australia generally assesses what is often called a granny flat as ancillary accommodation. PlanSA's ancillary accommodation guidance says planning approval is required to check that the accommodation is appropriately sited, alongside building approval. The state's Planning and Design Code applies through the property address, zone and overlays; a headline limit copied from another state is not a South Australian rule.
Before choosing a granny flat floor plan in South Australia, check the address in PlanSA, then ask the relevant authority about the proposed use, siting and approval documents. If your intention is to rent it, confirm the current approval conditions rather than assuming that the word 'ancillary' allows every rental arrangement. The site and intended occupation both need to match the approved proposal.
Tasmania: do not buy against a draft 90 m² rule
Tasmania uses the Tasmanian Planning Scheme's state provisions and local provisions for the municipality. The Tasmanian Planning Commission's 2026 amendment assessment concerns a proposal to increase the allowable size of secondary residences from 60 m² to 90 m². A proposal is not the same as an operative planning rule. Check the version in force for your municipality on the date you intend to lodge.
Ask your Tasmanian council whether the use qualifies as a secondary residence, what the current floor-area definition says, and whether your site triggers a planning permit because of zone or hazard controls. If a plan only works under an anticipated 90 m² rule, wait for official confirmation that it has commenced or choose a design assessed under current requirements.
ACT: check the Territory Plan, not a council list
The Australian Capital Territory does not have the same council-by-council planning system as the states. Its secondary-residence proposals are assessed under the Territory Plan and ACT approval processes. ACT Planning's development-approval guidance identifies secondary residences as a specific approval type and says they cannot be subdivided under the relevant ACT framework.
Check your block, lease conditions and current Territory Plan with ACT Planning before buying a drawing. Ask whether your proposal needs a development application, building approval, a lease variation or other documentation. A design sold for a different jurisdiction does not answer those ACT-specific questions.
Northern Territory: independent units have their own test
In the NT, the planning term is often dwelling – independent. NT Government guidance on building an independent unit says building approval is required. Planning approval is not needed in many cases only if the proposal meets the NT Planning Scheme requirements, including zoning, floor area and services. The government states that a 75 m² maximum applies in certain zones following an amendment, not automatically in every zone.
Before buying a design for Darwin, Palmerston or a regional NT property, verify the land's zone and the applicable assessment table. Check water, sewerage or on-site wastewater, power and any planning-permit trigger with the relevant NT authority and a registered building certifier. A building that could fit physically may still fail the services or land-use tests.
How to check your council before purchasing a granny flat design
- Identify the authority and property. Get the street address, lot and plan details, and the correct council or territory planning body. Ask for an address-specific assessment, not a generic brochure.
- Confirm the land-use definition. Is the proposal a secondary dwelling, ancillary accommodation, independent unit or dual occupancy? State whether it will house family, a long-term tenant or short-stay guests; those uses can trigger different requirements.
- Request the planning controls. Check zone, overlays, minimum lot area where relevant, building height, setbacks, site cover, private open space, parking, access and whether a main home must already exist.
- Check constraints that a floor plan cannot show. Flooding, bushfire, heritage, easements, slope, sewer lines, trees, coastal hazards and service capacity can limit placement or require specialist reports.
- Confirm the approval pathway. Ask whether a planning approval or development application is needed, who issues it, whether building approval is separate, and what plans or site survey must be lodged.
- Compare plans only after that answer. Check the proposed building's measured internal area, footprint, deck, stairs, windows and access against the rules that apply to your lot. Ask a local qualified professional whether adjustments are needed before buying a design.
Keep the council or authority's response and the date of the advice. Regulations change; an older email about a neighbour's property is not approval for yours. If you are choosing between two layouts, send both drawings and your property details for preliminary advice before committing to a particular design.
Choose a layout that can be assessed on your block
Australian House Design Group lists designs with different sizes; none should be assumed council-approved for your address. For example, GF1003-A Granny Flat is listed at 59.75 m², while GF1001 Granny Flat is listed at 93.6 m². That difference can matter where a jurisdiction defines a small second dwelling by area. But even the smaller design still needs a site and approval check, and different jurisdictions can measure area differently.
The catalogue is useful for comparing room layout, accessibility, windows and outdoor connection. Its limitation is that a ready-made plan cannot know your survey, easements, council overlays or approval conditions. Australian House Design Group offers site-specific custom drafting in Australia; ready-made digital plans can be purchased from other countries, but their buyers must check the rules that apply where they build. Do not buy a granny flat design on the assumption that its product name, size or marketing description is an approval.
FAQ
Do granny flats need council approval in Australia in 2026?
There is no single Australia-wide answer. Depending on the state, council, land zone and site, you may need planning approval, while building approval is a separate requirement; ask the relevant authority about your address before buying a design.
Can I build a 60 m² granny flat without a permit in Victoria?
A Victorian small second dwelling of 60 m² or less may avoid a planning permit in many cases, but it always needs a building permit. Lots under 300 m² in applicable residential zones and sites with special planning controls can require a planning permit.
Can I rent out my granny flat in Queensland?
Queensland permits secondary dwellings to be rented to anyone, but the statewide occupancy change did not remove development and building approval requirements. Existing approval conditions and fire-safety obligations must also be checked.
Is the 70 m² WA granny flat rule valid in every council?
No. WA's R-Codes contain a 70 m² internal-area provision for specified ancillary dwellings, but local planning controls and site conditions still apply. Confirm the assessment pathway with the property's local government.
Can I use a 90 m² granny flat design in Tasmania in 2026?
Do not assume a 90 m² secondary residence is allowed just because an increase has been proposed. Check whether the amendment is in force and what the current Tasmanian Planning Scheme and local provisions allow for your site.
Will a granny flat floor plan be approved on my block?
A catalogue floor plan is not a property-specific approval. Check zoning, siting, hazards, services and the applicable planning and building pathways with the relevant authority and a qualified local professional before purchase.
One last thing before you buy
The decisive question in 2026 is not 'which granny flat design looks right?' but 'which design can be assessed on this exact lot under today's rules?' Ask that first. Then use Australian House Design Group's plans to shortlist layouts that match the answer, rather than paying for a design and finding out afterwards that the block needs a different footprint or approval route.