Granny Flat Rules in 2025 For Wollongong, Illawarra, The Shoalhaven, Southern Highlands & Sutherland Shire: What You Need to Know Before You Build
- The Groovy Granny
- Oct 15
- 3 min read
Thinking about a granny flat in our local service are of the South Coast of NSW? Here’s a clear, up-to-date guide to NSW rules so you know what’s allowed, how approvals work, and what to check on your block before you start.
In NSW, a “granny flat” is called a secondary dwelling. It’s a self-contained home on the same lot as the main dwelling, and it’s generally permitted in residential zones R1–R5 across NSW.
CDC or DA — which approval path is right for you?
Most secondary dwellings are approved one of two ways:
CDC (Complying Development Certificate) — a fast-track approval issued by council or an accredited certifier if your design meets all State code standards. This can be significantly quicker than a DA. Planning Portal
DA (Development Application) — used when you don’t fully meet the code standards or your site has constraints. Wollongong City Council assesses DAs against the local LEP/DCP. City of Wollongong
Which is better? If your block and design tick all the boxes, CDC is usually faster. If not, DA can unlock bespoke designs or tricky sites. (We’ve broken this down here: CDC vs DA for Granny Flats.)
Where are granny flats permitted?
NSW planning policy allows secondary dwellings in most residential zones (R1–R5), and sometimes in other zones if your local LEP permits it. You cannot subdivide the lot to sell the granny flat separately.
Common development standards to expect (high level)
Exact controls depend on your approval path and local controls, but expect checks around:
Zoning and lot eligibility (confirm on the NSW Planning Portal / Section 10.7 planning certificate). Planning NSW
Maximum floor area and height per the relevant code/controls.
Setbacks, private open space, privacy, stormwater, and bushfire/flood where applicable. Planning NSW+1
Tip: Wollongong City Council provides specific guidance and the pathway for CDC or DA if you don’t meet CDC rules.
Our 9 Step Process
We know the best outcome only comes when everyone knows what we are doing together. So, our process ensures you're always in the know, from consultation to completion.
The process starts with getting a general understanding of what you want and then, through proposals and discussions, working towards a detailed agreement about precisely what your project includes in terms of design, build, timings, services, finishes and cost.
We are upfront that sometimes things can only be known after some work or checking is completed. For example, there may be underground engineering or services issues or custom changes, you may need different materials, etc. We flag this in the process and work with you to mitigate these “unknowns” in various ways.
Initial phone consultation to understand general requirements
Desktop assessment to review basic compliance and discuss cost estimate range
Site visit to gather information, discuss Granny Flat location
Presentation of Granny Flat proposal to client
Your response to the proposal with inclusions, exclusions, timing & costs
Signed agreement with deposit for design and planning phase
Design and planning process, building consent achieved for compliant properties
Building contract signed and building works commence
Practical completion achieved
Granny Flat FAQs
Is a granny flat allowed on my block?
Usually in R1–R5 zones, subject to standards. Check your zoning and site constraints first.
Do I need a DA?
Not if you qualify for CDC. If you don’t meet all Code standards or have site constraints, DA is the path.
Can I subdivide and sell the granny flat?
No — secondary dwellings can’t be subdivided off the primary lot.
What about bushfire or flood?
You’ll need additional assessment and design responses; eligibility can change. Check early.
Want To Know More?
Get a site-specific fixed quote for your property. We’ll confirm eligibility (CDC vs DA), provide a clear inclusions list, and map your build timeline.