CDC vs DA: What’s the Difference When Building a Granny Flat in Wollongong?

When building a granny flat (also known as a secondary dwelling) in Wollongong or the greater Illawarra region, one of the most important decisions is how to get it approved.

You’ve likely heard of CDC and DA — but what do they mean, and which one is better for your project?

At Wollongong Granny Flats (WGF), we help homeowners navigate this process every day. Below, we break down the key differences between these two approval methods and what it means for your budget, timeline, and site eligibility.

What is a CDC (Complying Development Certificate)?

A CDC is a fast-tracked approval process for building work that meets specific planning and design rules set by the NSW Government.

If your site and proposed granny flat meet all the criteria, you can skip council approval entirely and go through a private certifier instead.

✅ Pros of CDC:

• Faster approvals – often within 10–20 business days

• Lower fees compared to a DA

• More predictable process – all rules are predefined

• No public notification or objections from neighbours

❗ Limitations:

• Strict design and site criteria — no flexibility

• Not suitable for heritage items, bushfire-prone areas (above BAL 29), flood zones, etc.

• Your lot must be a specific size (typically 450m²+), and meet frontage and zoning rules

What is a DA (Development Application)?

A DA is a formal application submitted to your local council (e.g. Wollongong, Shellharbour, Kiama) requesting approval for your proposed build. It’s used when your design doesn’t comply with CDC rules, or if your site has constraints (like steep slope, bushfire risk, or heritage listing).

✅ Pros of DA:

• More design flexibility – greater scope for customisation

• Can build on more complex sites

• Ideal for properties with planning overlays or zoning issues

❗ Limitations:

• Takes longer – typically 6–12 weeks, sometimes more

• Higher application and consultant fees

• Public notification required – neighbours can object

• Council may impose additional conditions

  
  

Quick Comparison Table

Feature	CDC (Complying Development)	DA (Development Application)
Approval authority	Private Certifier	Local Council
Speed	10–20 business days	6–12+ weeks
Design flexibility	Limited (must meet strict rules)	Flexible
Cost	Lower	Higher (council fees, reports)
Public notice / objections	No	Yes (neighbour notification)
Suitable for heritage / flood / bushfire	No	Sometimes, with conditions
Best for	Standard granny flats	Unique or constrained properties

Can I Choose Either?

Not always. The site conditions and zoning will usually dictate your options.

A good rule of thumb:

• If your block is flat, over 450m², and has no overlays or constraints, a CDC is likely possible

• If your site has slope, heritage, flood or bushfire risks, or you want a custom design, a DA may be required

At WGF, we conduct a free desktop assessment of your block to check CDC eligibility. We’ll give you honest feedback — no guesswork.

Real Example: CDC vs DA in Action

• Debbie in Corrimal had a 600m² lot, flat and clear. We used a CDC, and her granny flat was approved in 13 days.

• Mark in Kiama had a site with a bushfire overlay and irregular setbacks. We prepared a DA and liaised with the council — approved in 9 weeks.

How Wollongong Granny Flats Help

Our in-house team helps with:

✅ Site assessment (CDC eligibility check)

✅ Design compliance with SEPP (State Environmental Planning Policy)

✅ Lodging CDC or DA on your behalf

✅ Liaising with certifiers or councils

✅ Fast-tracking where possible

Final Word: What’s Right for You?

There’s no “one size fits all.” But understanding your site conditions, your design goals, and the regulatory pathways available can save you months of delay and thousands in fees. 🛠️ At Wollongong Granny Flats, we handle the paperwork — so you don’t have to.

📞 Ready to start?

Request your free site assessment today and find out whether your site qualifies for fast CDC approval.

👉 Contact us now →

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