A granny flat is one of the most cost-effective ways to add rental income to an investment property — $90K–$180K in construction generates $300–$600/week in additional rent, potentially transforming a moderately yielding property into a strongly cash-flow positive investment. Rules vary significantly by state.
Secondary Dwelling Planning Rules — Key State Differences 2026
NSW — Most Permissive
CDC approval in most low-density zones — typically 10–15 business days. Max 60–80sqm. Strongest granny flat market in Australia.
QLD — Council by Council
Rules vary by council. Brisbane allows secondary dwellings code assessable in most zones. Max typically 80sqm.
VIC — DA Required
Planning permit required for most secondary dwellings. More complex than NSW’s CDC pathway but still viable.
WA, SA — Improving Frameworks
WA permits ancillary dwellings on most R20+ coded lots. SA permits in residential zones. Both simplified in recent years.
One Property at a time
Brick by Brick 🧱
General Advice Warning: This article is general in nature and does not constitute personal financial advice. Please consult a licensed financial adviser before making investment decisions.
