Secondary Dwelling Rules Differ Across Australian States (2026)
secondary dwelling rules Australia. Australia’s secondary dwelling rules remain state-specific. Tasmania’s draft 90sqm proposal highlights the patchwork of regulations across NSW, Victoria, and other jurisdictions. Here’s what property owners need to know in July 2026.
Tasmania: Draft 90sqm Proposal
Tasmania’s Draft Planning Scheme Amendment 01-2026 proposes lifting the secondary residence floor area cap from 60sqm to 90sqm. The amendment also clarifies that no additional parking is required.
The draft is not yet approved. The current legal maximum remains 60 square metres until the Tasmanian Planning Commission approves the amendment and it is gazetted.
The Housing Industry Association (HIA) lodged a submission on 22 July 2026 supporting the increase but calling for relaxed site coverage rules to make the larger floor area practical on suburban blocks.
New South Wales: CDC and DA Pathways
Complying Development Certificate (CDC)
The fast-track option under SEPP (Housing) 2021 allows granny flats up to 60 square metres without council discretion, provided the development meets design standards. No extra parking is required.
Development Application (DA)
Granny flats over 60sqm (up to 120sqm in some cases) require a DA. Councils assess design, setbacks, and neighbourhood character. Approval timelines vary.
NSW’s framework is the most flexible in Australia, though CDC eligibility depends on zoning and heritage overlays. Always check with a private certifier or council before assuming CDC applies.
Victoria: Part 5 and Secondary Dwellings
Victoria’s planning system allows small second dwellings on most residential lots as-of-right, typically capped at 60sqm. The approval pathway varies by zone:
- General Residential Zone (GRZ): Secondary dwellings under 60sqm usually exempt from planning permits.
- Neighbourhood Residential Zone (NRZ): Stricter rules; may require a permit even for small secondary dwellings.
- Overlays: Heritage, Design and Development Overlays (DDO), or neighbourhood character overlays can override the exemption.
Building permits are always required under the Building Code of Australia. Planning exemptions do not bypass building compliance.
State-by-State Comparison
| State | Max Floor Area (Typical) | Approval Pathway | Parking Requirement |
|---|---|---|---|
| NSW | 60sqm (CDC), up to 120sqm (DA) | CDC or DA | None under CDC |
| Victoria | 60sqm (GRZ) | Often exempt (permit required in NRZ or under overlays) | Varies by zone |
| Tasmania | 60sqm (current), 90sqm (draft proposal) | Council approval | None (proposed clarification) |
| Queensland | 60sqm (typical) | Council DA or code assessment | Depends on council scheme |
| South Australia | Varies by zone and council | Planning consent required | Council-specific |
Dual Occupancy vs Secondary Dwelling
A terms are not interchangeable. A dual occupancy typically involves two separate dwellings of comparable size on one lot, often with subdivision potential. A secondary dwelling is a smaller, ancillary structure subordinate to the primary residence.
- Dual occupancy: Requires council DA in most states. May trigger infrastructure charges and higher building standards.
- Secondary dwelling: Fast-track pathways (CDC in NSW, exemptions in VIC GRZ) available if design standards are met.
Families building granny flats for ageing parents or adult children typically pursue secondary dwelling approval, not dual occupancy.
Why State Rules Differ
Australia’s planning system is state-managed, not federal. Each jurisdiction sets its own secondary dwelling framework based on housing policy priorities, infrastructure capacity, and community expectations around neighbourhood character.
Recent reforms in NSW, Victoria, and now Tasmania reflect growing demand for affordable housing, multi-generational living, and ageing-in-place options. Other states have been slower to adopt fast-track pathways.
Frequently Asked Questions
Can I build a 90sqm granny flat in Tasmania now?
No. The draft amendment proposing 90sqm is not yet approved. The current legal maximum remains 60 square metres until the planning scheme is updated and gazetted.
Do NSW granny flats always qualify for CDC?
No. CDC eligibility depends on zoning, heritage overlays, and design compliance. Some sites require a DA even for 60sqm granny flats. Check with a private certifier or council before assuming CDC applies.
Does Victoria require parking for secondary dwellings?
It varies by zone and council. General Residential Zone (GRZ) often waives parking for secondary dwellings under 60sqm, but Neighbourhood Residential Zone (NRZ) and overlays may impose stricter rules.
Which state has the most flexible granny flat rules?
NSW’s CDC pathway is the most flexible, allowing 60sqm secondary dwellings without council discretion in most residential zones. Victoria’s exemptions are also generous in GRZ areas.
Are granny flat rules the same in all councils within a state?
No. While state planning schemes set the baseline, individual councils can apply local policies, overlays, and design standards that restrict or modify approval pathways.
Disclaimer: This article is for general information only and is not planning or legal advice. Always confirm current rules with your local council or a qualified town planner before submitting development applications.
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
- Victorian Building AuthorityBuilding Act 1993 / small second dwelling settings
- QBCC (Queensland)Queensland Building and Construction Commission licensing
