Plain English Summary
Most granny flats in NSW don't need council approval
In 2009, NSW changed the rules to let homeowners build a granny flat without going through council — as long as your block meets specific size and zoning requirements. A private certifier approves it directly. If your block doesn't qualify, you go through council with a Development Application. The answer depends almost entirely on your specific block.
The three approval paths for a NSW granny flat
Most common
CDC — Fast-Track, no council
Block is 450m² or more, no heritage or bushfire overlays, design meets the state code. Private certifier approves in around 20 business days. No council. No neighbour notification. Approval fees typically $3,000 to $8,000.
Longer path
DA — Council Approval Required
Block is under 450m², has a heritage or flood constraint, or design exceeds CDC limits. Lodge with council, neighbours notified. Typically 8 to 16 weeks. Can still be approved — just takes longer.
Rare cases
Not permitted
Some properties cannot have a granny flat at all — strata title, community title, or certain non-residential zones. Worth checking your zoning before planning anything.
What your block needs to qualify for fast-track approval
Minimum block size
Your total land area, not just the house footprint
450m²
Minimum frontage width
Measured at the building line of the existing dwelling
12 metres
Zoning
Must be residential — R1, R2, R3, R4 or RU5
Residential
Maximum granny flat size
Internal floor area only. Decks and carports are separate.
60m²
No heritage listing
Heritage listed homes or streets cannot use the CDC pathway
Required
No bushfire overlay
Bushfire-prone land cannot use the fast-track path
Required
Existing home on the block
The granny flat must sit alongside an existing primary home
Required
Not sure about your block? Check your land size on your council rates notice. For heritage, flood and bushfire overlays search your address free at planningportal.nsw.gov.au — or use the ReadyBuild tool below and it will guide you through it.
Check your specific block in 2 minutes
Answer 5 plain English questions. ReadyBuild tells you exactly which approval pathway applies to your granny flat — CDC, DA, or not permitted. Free. Instant.
Check my block nowCommon questions
Can I build a granny flat on a 300m² block in NSW?⌄
Not using the fast-track CDC pathway — that requires a minimum of 450m². However you may still be able to get approval through a Development Application (DA) to council. A DA assesses your project on its merits, so even undersized blocks can sometimes get approval. It takes longer and is less predictable. A free call with RO-KA Studio will tell you quickly what is realistic for your specific block.
Does a granny flat need to be detached from the main house?⌄
No. A granny flat can be detached, attached or internal. All three can qualify for the CDC pathway as long as the block and design requirements are met.
Can I rent out my granny flat in NSW?⌄
Yes. A properly approved granny flat in NSW can be rented to anyone — it does not have to be a family member. This is one of the most popular reasons to build one. Rental income can significantly offset the build cost over time.
What happens if I build without approval?⌄
Serious risk. An unapproved structure can result in council fines, a demolition order, difficulty selling your property and issues with your home insurance. The approval process exists to protect you. It is not worth skipping.
How do I check if my property has heritage or bushfire overlays?⌄
The fastest free method is the NSW Planning Portal Spatial Viewer at planningportal.nsw.gov.au. Enter your address and it shows all overlays. Takes about 5 minutes. Or use the ReadyBuild checker — it guides you through this step if you're not sure.
Can I build a granny flat in Newcastle or the Hunter region?⌄
Yes. Newcastle, Lake Macquarie, Maitland, Cessnock and the broader Hunter region all follow NSW state planning rules. Most standard residential blocks in these areas are 450m² or more and are eligible. Some older inner-Newcastle properties in heritage conservation areas will need a DA.