Is a granny flat the same as subdividing? No. A granny flat is a second, smaller home built on the same lot and the same title as the main house, while a subdivision creates a new lot with its own title. The two are approved under different rules, and in several states the rules expressly stop a granny flat being split off onto its own title.
The name changes across the country. NSW and Queensland say secondary dwelling, Victoria says small second dwelling, South Australia says ancillary accommodation, WA says ancillary dwelling, Tasmania and the ACT say secondary residence, and the NT says independent unit. This guide compares the two options, then sets out the names, limits and titling rules in each state and territory.
Granny flat vs subdivision at a glance
| Granny flat | Subdivision | |
|---|---|---|
| What you get | A second, smaller home on the same lot as the main house | A new lot of land (or a strata, community or unit title lot) |
| Title | Stays on the one title with the main house | Each new lot gets its own title once the plan is registered |
| Approval type | A building approval, plus planning approval depending on the state, zone and overlays | A subdivision approval under state planning law, then registration of a new plan |
| Typical tests | Floor area cap, one per lot, siting and setbacks, and in some states shared access and service connections | Minimum lot size or site area, frontage and access, servicing, and constraints such as bushfire, flood and heritage |
| Who to talk to | Your council's planning team and the certifier who issues building approval | A licensed surveyor and a town planner, and the body that approves subdivision in your state |
What counts as a granny flat
The official descriptions tie a granny flat to a main house. NSW Planning calls it "a self-contained dwelling located within, attached to, or separate from another dwelling on the same site". Queensland's planning department says a secondary dwelling "is used in conjunction with, and subordinate to, another dwelling on the same lot".
Most places then add limits that keep it secondary:
- A floor area cap, which differs between states and sometimes between zones (see the table below).
- One per lot. In NSW, the development of a secondary dwelling "can only result in there being one principal dwelling and one secondary dwelling on the site". In the ACT the limit is one per block.
- Shared access and services. Tasmania's definition requires a secondary residence to share access and parking, and water, sewerage, gas, electricity and telecommunications connections and meters, with the main house. In SA, the deemed-to-satisfy criteria say ancillary accommodation does not have separate connections to utilities and services.
What counts as a subdivision
A subdivision divides land into new lots, each able to carry its own title. It is assessed against a different set of rules: the minimum lot size or site area for your zone, frontage and access to a road, connection to water, sewer and other services, and overlays such as bushfire, flood and heritage.
Who approves it differs by state:
- NSW: usually a development application to the local council, then a subdivision certificate and registration of the plan with NSW Land Registry Services.
- VIC: a planning permit from council, then certification of the plan under the Subdivision Act 1988. The titles only exist once Land Services Victoria registers the plan.
- QLD: the official term is reconfiguring a lot, and your local council is usually the assessment manager.
- SA: the official term is land division, and you need land division consent and planning consent, which together form your development approval.
- WA: the Western Australian Planning Commission (WAPC) approves subdivision, not your council.
- TAS: a planning permit from your council, which later seals the final plan of survey.
- ACT: a development application to the Territory Planning Authority. Subdividing means changing a Crown lease.
- NT: a development permit, usually from the Development Consent Authority.
Our state guides explain each process in full.
Granny flat names and limits by state
| State | Official name | Size limit (as stated) | Planning approval | Separate title for the granny flat |
|---|---|---|---|---|
| NSW | Secondary dwelling | Set by the Housing SEPP. Hornsby Shire Council, for example, lists 60 m² in residential zones | Complying development (lot of at least 450 m²) or a development application | No. A lot with a secondary dwelling cannot be subdivided |
| VIC | Small second dwelling | 60 m² or less | No planning permit on most residential and rural properties; building permit always required | No. Cannot be subdivided or separately sold off |
| QLD | Secondary dwelling | Set by your council's planning scheme | Building approval; check with council whether development approval is needed | No statewide rule found; a new lot is reconfiguring a lot |
| SA | Ancillary accommodation | Floor area not exceeding 70 m² (deemed-to-satisfy) | Development approval (planning and building) | No rule found; a new allotment needs land division consent |
| WA | Ancillary dwelling | Must not exceed 70 m² | Exempt from development approval if deemed-to-comply; building permit always required | No rule found; a new lot needs WAPC approval |
| TAS | Secondary residence | Not more than 60 m² now; 90 m² proposed, not in force | Set by the zone use table; the draft would make it No Permit Required in some zones | Strata conversion question still before the Commission |
| ACT | Secondary residence | Up to 90 m², one per block | Permitted use in RZ1 and RZ2; development application in ACT Planning's example | No. Cannot be given a separate title or unit title |
| NT | Independent unit (dwelling-independent) | 75 m² in certain zones | No development permit if the use is permitted, no overlays apply and all requirements are met; building approval needed | Not through a unit title scheme. Freehold only if every subdivision requirement is met |
"No rule found" means the official pages we read did not state a rule either way. It does not mean a separate title is available. Any new lot still has to meet the subdivision rules for the land.
State by state
New South Wales. NSW Planning says a secondary dwelling may be built with consent or as complying development, depending on meeting requirements including lot size and floor area in the Housing SEPP. One requirement for complying development is a lot of at least 450 m². Hornsby Shire Council, for example, lists a maximum of 60 m² in residential zones and says secondary dwellings "must remain on the same title as the principal dwelling and can only be sold together". NSW Planning states the rule directly: "A lot on which a secondary dwelling is constructed cannot be subdivided." See our NSW subdivision guide.
Victoria. Amendment VC253 changed the rules on 14 December 2023. Planning Victoria says a small second home is "a dwelling that is 60 square metres or less with a kitchen, bathroom and toilet, located on the same lot as an existing home". It "can be built on most properties in residential and rural zones without a planning permit", but flooding, environmental or other special planning controls can change that, and Clause 54 applies where the lot is less than 300 m² in a residential zone. A building permit is always required, and a small second home "cannot be subdivided or separately sold off from the main home". The General Residential Zone clause adds that a permit must not be granted to create a separate lot for land containing a small second dwelling. See our Victoria subdivision guide.
Queensland. Changes to the Planning Regulation took effect on 26 September 2022 and removed a restriction on how members of a household live together. The state says any new secondary dwelling needs building approval, and that you still need to speak with your council to understand whether development approval is needed. Size and assessment rules sit in each council's planning scheme. Brisbane City Council, for example, has proposed a City Plan amendment that would limit the size of secondary dwellings relative to the size of the site. Creating a new lot is reconfiguring a lot, assessed against your council's planning scheme. See our Queensland subdivision guide.
South Australia. Under the Ancillary Accommodation and Student Accommodation Definitions Review Code Amendment, the Planning and Design Code defines ancillary accommodation as accommodation located on the same site as an existing dwelling and ancillary to it, which can be (but need not be) self-contained and contains no more than 2 bedrooms. The SA Government announced on 22 November 2024 that the maximum had increased from 60 to 70 square metres. The amendment's deemed-to-satisfy criteria say it "has a floor area not exceeding 70m2" and does not have separate connections to utilities and services, and its performance outcome calls for shared utilities and shared open space. The City of Onkaparinga says development approval, covering planning and building, is needed "regardless of how small or big" it is. A separate allotment is a land division, with Torrens or community title available but no new strata. See our SA subdivision guide.
Western Australia. In a statement on 30 January 2024, the WA Government said compliant granny flats "on residential lots of any size" no longer require development approval if they meet the R-Codes' deemed-to-comply provisions. An ancillary dwelling must meet setback requirements and "must not exceed 70m2", and the previous 350 m² minimum lot size was removed. The Town of East Fremantle describes it as attached to, integrated with or detached from a single house on the same lot, and requires development approval for Category A and B heritage properties. The City of Gosnells says the exemption does not apply to land zoned Rural, and the City of Joondalup says a building permit is required for all ancillary dwellings. Any new lot needs WAPC approval and must meet the R-Code site areas, for example a 350 m² minimum and 450 m² average at R20. See our WA subdivision guide.
Tasmania. The State Planning Provisions define a secondary residence as an additional, self-contained residence with a gross floor area not more than 60 m², appurtenant to a single dwelling and sharing its access, parking and service connections and meters. A draft amendment, SPP Amendment 01/2026, would raise the limit to 90 m². It was exhibited from 10 June to 22 July 2026 and heard on 16 and 17 September 2026. On 21 September 2026 the Tasmanian Planning Commission asked the State Planning Office for more information, with reply submissions due 14 October 2026. As at 4 October 2026 no decision had been published, so the 60 m² limit applies. The Commission's first question was whether the amendment should "preclude the conversion of a primary residence and secondary residence to strata title". Separately titled lots are a subdivision, with a 450 m² lot and 12 m frontage as the General Residential Zone acceptable solution. See our Tasmania subdivision guide and our news article on the 90 m² proposal.
Australian Capital Territory. In RZ1 and RZ2 the Residential Zones Policy lists secondary residences as a permitted use. A secondary residence can be up to 90 m², one per block, alongside single dwelling housing, but it cannot be given a separate title or unit title (F01 Assessment Requirement 5). ACT Planning's worked example of a granny flat involved a development application and, for that lease, a lease variation, and notes it "could not be separately titled and/or sold in the future". A separate Bill, introduced on 24 March 2026, would give all single-dwelling Crown leases an automatic entitlement to a secondary residence. In June 2026 the Government said those changes were expected to begin later in 2026, subject to passage. See our ACT subdivision guide.
Northern Territory. An independent unit or granny flat is a "dwelling – independent" under the NT Planning Scheme 2020. Since 1 December 2023 its maximum floor area is 75 m² in certain zones. You don't need a development permit if the use is permitted, no overlays apply and you meet all the relevant requirements, but you need building approval from an NT registered building certifier. The NT Government says: "You can't create a separate title for an independent unit through a unit title scheme subdivision." A separate freehold title is only possible if the proposal meets every subdivision requirement, including the minimum lot size, which is 800 m² in established Zone LR areas. A proposed amendment to cut that to 450 m² had not been decided as at 2 October 2026. See our NT subdivision guide.
Can a granny flat be subdivided later?
Generally, not as a granny flat. In NSW, Victoria, the ACT and the NT (for unit titles), the rules expressly stop it, and in Tasmania the strata question is still open. Everywhere, a separate title for a second home is a subdivision, assessed against the subdivision rules for the land rather than the granny flat rules.
If you want two homes on separate titles, the question becomes a subdivision or dual occupancy question from the start. Each lot must meet the minimum lot size or site area, frontage, access and servicing rules for the zone. Our guide to subdividing a dual occupancy compares those rules across the states.
Questions to answer for your block
- What is your zone, and does it allow a granny flat, a second lot, or both?
- What floor area cap and siting rules apply to a granny flat in your state and council area?
- Do overlays such as heritage, flood or bushfire take away a no-permit or exempt pathway?
- What minimum lot size, frontage and access would each new lot need?
You can see how a report sets out these issues for one address in our sample report.
Check your own block
A Subdivision Checker report applies these rules to one address: planning and zoning, heritage, environment, bushfire, flood, servicing, contamination and title, plus indicative costs. It is a starting point, not a substitute for advice from a licensed surveyor or town planner. Order a report for your address.
Frequently asked questions
What is the difference between a granny flat and a subdivision?
A granny flat is a second, smaller home on the same lot and the same title as the main house. A subdivision creates a new lot with its own title. They are approved under different rules: a granny flat against size and siting limits, a subdivision against minimum lot size, frontage, access and servicing.
Can a granny flat be subdivided?
In several places the rules say no. In NSW a lot on which a secondary dwelling is built cannot be subdivided. In Victoria a small second dwelling cannot be subdivided or separately sold off from the main home. In the ACT a secondary residence cannot be given a separate title or unit title, and in the NT an independent unit cannot get a separate title through a unit title scheme. Elsewhere, a second home on its own title needs a subdivision that meets every subdivision rule for the land.
Do I need approval to build a granny flat?
Usually you need at least a building approval, and sometimes planning approval too. Victoria says a building permit is always required, although most properties in residential and rural zones need no planning permit. In WA a compliant ancillary dwelling is generally exempt from development approval but still needs a building permit. In NSW it is complying development or a development application. Check with your council.
How big can a granny flat be?
It depends on the state. Victoria's small second dwelling is 60 m² or less, SA's ancillary accommodation deemed-to-satisfy limit is 70 m², WA's ancillary dwelling must not exceed 70 m², Tasmania's secondary residence is currently not more than 60 m², the ACT allows up to 90 m² and the NT allows up to 75 m² in certain zones. In NSW and Queensland the limit comes from the state policy or your council's planning scheme.
Is Tasmania's 90 m² granny flat limit in force?
No. As at 4 October 2026 it was a draft amendment to the State Planning Provisions, SPP Amendment 01/2026, and no decision had been published. Until the Minister makes it, a secondary residence has a gross floor area of not more than 60 m².
Sources
- Secondary dwellings (NSW Planning)
- Secondary dwelling (Hornsby Shire Council)
- Small second dwellings (Planning Victoria)
- Victoria Planning Provisions, Clause 32.08 General Residential Zone
- Changes to secondary dwellings (Queensland Department of State Development, Infrastructure and Planning)
- Secondary dwellings providing housing solutions (Queensland Government)
- Major amendment package L (Brisbane City Council)
- Ancillary Accommodation and Student Accommodation Definitions Review Code Amendment, approved (PlanSA)
- Bigger, more accessible granny flats (SA Department for Housing and Urban Development)
- Ancillary accommodation: granny flats, tiny homes and transportables (City of Onkaparinga)
- A guide to subdividing land within South Australia (Land Services SA)
- More granny flat exemptions give another boost for housing choice (WA Government media statement)
- Ancillary dwelling (granny flats) (City of Joondalup)
- Ancillary dwellings (City of Gosnells)
- Ancillary dwellings (granny flats) (Town of East Fremantle)
- Residential Design Codes Volume 1 (10 April 2026)
- Subdivision application forms, guidelines and checklists (DPLH)
- Tasmanian Planning Scheme: State Planning Provisions (State Planning Office)
- SPP Amendment 01/2026 – Secondary Residences (State Planning Office)
- AM-SPP-01-2026 (Tasmanian Planning Commission)
- Commission direction, 21 September 2026 (Tasmanian Planning Commission)
- Territory Plan 2023, F01 Subdivision Policy (ACT Legislation Register)
- Territory Plan 2023, E01 Residential Zones Policy (ACT Legislation Register)
- Case study 2: Grant and his granny flat (ACT Planning)
- Enabling more Missing Middle housing for Canberrans (ACT Government media release, 24 March 2026)
- Building an independent unit (NT Government)
- NT Planning Scheme 2020, Part 6: Subdivision and Consolidation Requirements
This guide is general information only, current at October 2026. Rules, fees and maps change, and every block is different. Speak to a licensed surveyor or town planner about your property.