Granny Flat Regulations Australia 2026 State-by-State Comparison
Granny flat regulations Australia are not national: each state sets its own size cap, setbacks and approval path.
NSW uses Housing SEPP CDC rules at 60 m² for many backyard secondary dwellings. Queensland allows up to 80 m² GFA in many metro areas, and Western Australia still talks about ancillary dwellings under the R-Codes. Use the interactive rules by state hub for the comparison table with official .gov.au links.
National comparison at a glance
| State | Typical max size | Fast-track pathway | Official source | Our guide |
|---|---|---|---|---|
| NSW | 60 m² internal | CDC via Housing SEPP | NSW Planning Portal | NSW CDC vs DA |
| VIC | 60 m² typical | Part 5 / VicSmart | planning.vic.gov.au | VIC rules |
| QLD | 80 m² GFA metro | Accepted development | planning.qld.gov.au | QLD rules |
| WA | ~70 m² (R-Codes) | Deemed-to-comply / approval | WA DPLH | WA guide |
| SA | 60 m² typical | Code / DA | PlanSA | SA guide |
| TAS | Up to 90 m² some zones | Permit / exempt | planning.tas.gov.au | TAS guide |
How approval pathways differ
New South Wales separates Complying Development (CDC) from Development Application (DA) under the Housing SEPP. A CDC through a private certifier is commonly the fastest route when every standard is met (NSW complying development). But CDC isn’t a rubber stamp. If your lot has a flood, bushfire or heritage overlay, you’ll usually drop to a DA even when the 60 m² envelope looks fine on paper.
Victoria uses the Victoria Planning Provisions and local schedules. Small second dwellings can qualify for streamlined assessment when they meet preset standards (VIC small second dwelling guide). You still need a building permit. Don’t skip that step because the planning permit disappeared on many lots.
Queensland distinguishes accepted development from assessable development under the Planning Act 2016 (QLD planning). So a Gold Coast overlay can still force a DA on a plan that would sail through as accepted development in another LGA.
Planning tools before you lodge
Don’t order a kit from a national brochure until you’ve screened the lot. Size caps travel better than setbacks, parking and overlay rules. A 60 m² plan that works in Penrith can fail in inner Melbourne or on a koala overlay in south-east Queensland.
- Approval pathway wizard – CDC vs DA likelihood by state
- Setback checker – size and setback screen
- Cost calculator – budget preliminaries including council fees
- Cost breakdown by line item
- ATO granny flat agreement – family funding and CGT
If you’re comparing two states because you own land in both, read the dedicated guide for each title, not this snapshot. The table above is a map, not a lodgement pack.
Frequently Asked Questions
Which state has the largest granny flat size limit?
Tasmania can allow larger ancillary dwellings in some zones (up to about 90 m²). Queensland metro commonly allows 80 m² GFA. NSW and Victoria commonly use 60 m² internal for fast-track pathways.
Can I use one national floor plan everywhere?
Rarely. Setbacks, height, parking and utility connections vary by council overlay. Always adapt drawings to your lot report before you order a kit.
What else should I verify locally?
Check flood, bushfire and airport noise overlays on your title before you order a kit. Council pre-lodgement meetings are often free and catch show-stoppers early.
How much does council approval add to your build budget?
Council and certifier fees sit outside the builder quote. In NSW, a CDC pathway through a private certifier often lands between roughly $3,000 and $8,000 once survey, BASIX and Sydney Water checks are included, while a full DA can cost more because of longer consultant time and holding costs. Victoria and Queensland use different fee schedules, so treat any single number as a starting point. Model your own project in our cost calculator, then compare supplier quotes through get a quote when your footprint is settled.
What design choices affect approval speed?
Setbacks, height, floor area and tree protection overlays decide whether you stay on a fast CDC track or drop to a slower DA. Staying under common 60 sqm internal caps, keeping adequate side and rear setbacks and connecting services without major easement conflicts usually keeps the pathway simpler. If your block is sloped, flood-affected or heritage-listed, expect extra reports before council or your certifier can sign off. Use the setback checker and approval wizard against your address before you pay for custom drawings.
Primary sources
These cards are an editorial summary of official pages. The Granny Flat Guide is not a certifier, council or licensed builder. Check the live official URL before you lodge or sign.
- Your Home (Australian Government)Your Home: Australia's guide to environmentally sustainable homes
- Australian Building Codes BoardNational Construction Code
- NSW Planning PortalState Environmental Planning Policy (Housing) 2021
- Victorian Building AuthorityBuilding Act 1993 / small second dwelling settings
- Queensland PlanningPlanning Act 2016
- WA Planning (DPLH)Planning and Development Act 2005
- PlanSA (South Australia)Planning, Development and Infrastructure Act 2016
- QBCC (Queensland)Queensland Building and Construction Commission licensing
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