If you are thinking about building a granny flat in NSW, the approval process is one of the first things you will need to understand. It is not as complicated as it sounds — but it does need to happen before any construction begins. Skip it, and you risk significant fines, forced removal, and serious headaches when you try to sell your property.
The short answer is that you need either a Complying Development Certificate (CDC) or a Development Application (DA). Which path you take depends on your property and its zoning. Here is what you need to know.
First: Check Whether Your Property Is Eligible
Before approval can even begin, your property needs to meet some basic eligibility requirements under the State Environmental Planning Policy (Housing) 2021. As a starting point, your property must:
- Be at least 450 square metres in size
- Be in a residential zone (R1 to R4)
- Have someone living in the main house — you cannot build a granny flat on vacant land
- Only have one secondary dwelling — if you already have a granny flat or a duplex, you cannot add another
Your 10.7 Planning Certificate (formerly known as the 149 Certificate) is the key document for checking zoning and any flags on your land — such as heritage listing, bushfire zone, flood zone, or mine subsidence. These do not automatically disqualify your property, but they do affect which approval path you will need and may add to the cost.
The Two Approval Pathways: CDC vs DA
Once your property has been assessed as eligible, your builder will determine which of the two approval pathways applies to your situation.
Complying Development Certificate (CDC)
A CDC is the most common approval path for granny flats in NSW. It is assessed by a private certifier — not your local council — which makes it faster. On straightforward sites, CDC approval can come through in as little as 10 days.
To use the CDC pathway, your property and the proposed granny flat must comply with all the rules set out in the SEPP. If everything stacks up, the certifier can issue approval without council involvement.
Development Application (DA)
A DA goes through your local council and takes longer — typically 6 to 8 weeks, sometimes more depending on your council and the complexity of the application. You will generally need a DA if your property is in a heritage zone, bushfire zone, flood zone, or mine subsidence area, or if the proposed build does not fully comply with SEPP requirements.
A DA gives the council more flexibility to assess your application on its individual merits, but it also means a longer wait and a less predictable outcome.
CDC vs DA at a Glance
| Criteria | CDC (Complying Development) | DA (Development Application) |
| Assessed by | Private certifier | Local council |
| Typical timeframe | 10 days to a few weeks | 6 to 8+ weeks (varies by council) |
| When it applies | Property meets all SEPP criteria | Property is in heritage, bushfire, flood zone, or does not meet SEPP |
| Flexibility | Less — must comply strictly with SEPP rules | More — council can consider individual circumstances |
| Who prepares it | Your builder and certifier | Your builder and council |
What Documents Are Required for Approval?
Regardless of which pathway applies, a full set of documents is required before approval can be granted. These typically include:
- Full architectural plans prepared by a registered architect
- Structural engineering report
- Hydraulic engineering report
- BASIX certificate (NSW energy and water efficiency assessment)
- Sewer diagram and Title Search
- 10.7 Planning Certificate
- Site-specific reports where required — for example, a Bushfire Attack Level (BAL) assessment or flood report
Gathering and preparing these documents is your builder’s job, not yours. If a builder expects you to organise any of this paperwork independently, that is worth questioning.
The Approval Process: Step by Step
- Site assessment — Your builder checks your Title Search, Sewer Diagram, and 10.7 Certificate to identify any flags and confirm the correct approval path.
- Design finalised — You work with the builder’s architect to finalise the plans. This must happen before lodging for approval.
- Documents prepared — The builder assembles all required plans, engineering reports, and certificates.
- Lodgement — The application is lodged with either a private certifier (CDC) or local council (DA).
- Approval issued — Once approved, construction can legally begin. You make your colour and material selections during this stage.
- Construction and handover — Building begins on the approved plans. Your builder manages the build and keeps you informed throughout.
For a full breakdown of Amescorp’s end-to-end process, visit amescorp.com.au/process/.
Frequently Asked Questions
How do I get approval for a granny flat in NSW?
You need either a Complying Development Certificate (CDC) from a private certifier, or a Development Application (DA) from your local council. Which one applies depends on your property’s zoning and any special overlays such as heritage, bushfire, or flood zones. A reputable builder will determine the correct path and manage the entire process on your behalf.
What is the difference between a CDC and a DA for a granny flat?
A CDC is faster — it is assessed by a private certifier and can be approved in as little as 10 days on eligible properties. A DA goes through your local council and typically takes 6 to 8 weeks or more. Properties that do not fully meet SEPP requirements will generally need a DA.
What land size do I need to build a granny flat in NSW?
Your property must be at least 450 square metres to qualify for a granny flat of up to 60 square metres under current NSW planning rules. Your property must also be in a residential zone (R1 to R4) and have the main dwelling occupied.
How long does granny flat approval take in NSW?
CDC approval can take as little as 10 days on straightforward sites. DA approval typically takes 6 to 8 weeks, though this varies depending on the council and the complexity of the application.
Do I have to manage the approval process myself?
No — and you should not have to. Amescorp manages the entire approval process on your behalf, including all document preparation, lodgement, and communication with certifiers or council. You focus on the design decisions; the builder handles the paperwork.
