You’ve got the dream. A bigger kitchen that opens onto the backyard, maybe a fourth bedroom for the kid who has finally outgrown sharing. You’ve scrolled Pinterest at midnight. You’ve measured the wall with a tape you found in the junk drawer.
Then a mate says, “Don’t forget council.” And just like that, the mood drops faster than a soggy sponge cake.
Here’s the thing. I’d say most people think council approval for an extension is one big, scary, months-long slog. Sometimes it is. But often it isn’t. Around the Illawarra, plenty of extensions skip the full council process altogether, while others need it for reasons you’d never guess (hello, escarpment views and old sandstone cottages).
So let’s sort it out. Whether you’re in Wollongong, Shellharbour or Kiama, this guide walks you through which approval path you’re probably on, what trips people up locally, and what to do first.
So, do you need council approval for an extension? The short answer
Maybe, maybe not, and it depends on your block. In NSW, an extension usually lands in one of three buckets. Which bucket you’re in decides how long you wait and who signs off.
| Pathway | What it means | Who approves it | Typical feel |
| Exempt development | Tiny, low-impact jobs that need no approval at all | Nobody (you still follow the rules) | Quick and simple |
| Complying development (CDC) | A fast-tracked certificate if your plans tick every box in the Housing Code | Council or a private certifier | Faster, but strict |
| Development application (DA) | A full assessment because your plans or site don’t fit the fast lane | Your local council | Slower, more flexible |
The NSW Government describes the Housing Code as a set of clear, simple planning rules for fast-tracked approval, including for renovations and extensions. If your plans can’t meet those rules, you lodge a DA with your local council instead.
So it’s less “Will council say yes?” and more “Which door do I walk through?”
Exempt development: when you don’t need approval at all
Let me be honest. A full-blown room addition is rarely exempt. Exempt development is for the small stuff: certain low decks, pergolas, sheds and similar minor structures, as long as they meet set limits on size, height and distance from your boundary.
Think of it as the “no paperwork” lane. Sounds lovely. The catch? The limits are tight, and they change depending on your zone, your lot size, and whether your land has special flags on it (more on that soon).
A few things to keep in mind:
- Exempt doesn’t mean rule-free. You still have to meet the conditions, or it stops being exempt.
- It rarely covers a proper extension. If you’re adding a bedroom, a bathroom or a second storey, you can pretty much count this lane out.
- Check the specifics before you build. Council’s planning team can confirm what your property allows.
I always tell people this: if you’re even a little unsure, ask first. Pulling down a pergola is a lot less fun than planning one.
Complying development: the fast lane for a house extension
This is where most standard extensions can land, and it’s the bit people overlook. A Complying Development Certificate (CDC) is a fast-tracked approval. You don’t go through a full council assessment. Instead, your plans are checked against a fixed list of rules, and if you meet every single one, you get the certificate.
Those rules sit in the NSW Housing Code. According to the NSW Planning Portal, the standards cover:
- maximum building height
- maximum floor area
- minimum distance from roads and boundaries (setbacks)
- minimum landscaped area
- privacy for your neighbours
The Housing Code applies in certain residential zones (the Planning Portal lists R1, R2, R3, R4 and RU5), and some of the numbers shift with your lot size. NSW Parliament’s research notes that lots are grouped into size bands, so a 450 square metre block and a 900 square metre block don’t play by the same rules.
A CDC can be issued by your council or by an accredited private certifier. And if your home needs it, you’ll usually need a BASIX certificate too, which is the NSW sustainability check for water and energy.
Here’s the honest part. CDC is all-or-nothing. Miss one setback by 300 millimetres and you’re out of the fast lane. It’s like a bouncer who has never once been talked around.
When you need council approval for an extension in Wollongong, Shellharbour or Kiama
Now the local bit. The Illawarra isn’t a flat, boring grid of identical blocks. We’ve got an escarpment, a lake, a long coastline, creeks that flood and bush that burns. Each of those can push you out of the CDC lane and into a DA.
Shellharbour’s own planning plan (the Local Environmental Plan 2013) spells out its aims clearly. It says it wants to protect the Illawarra Escarpment, Lake Illawarra and the coastline, as well as heritage and native vegetation. That tells you what the planners care about when they look at your extension.
Here’s a quick guide to the usual triggers. It’s a starting point, not a verdict.
| Situation | Why it can mean a DA | Where it’s common |
| Heritage item or heritage conservation area | Extra rules to protect character and old buildings | Kiama’s historic streets, older Wollongong and Shellharbour villages |
| Bushfire-prone land | A bushfire report is often needed, and Shellharbour’s DA checklist lists one | Escarpment edges, rural fringes |
| Flood-affected land | Floor levels and design may need closer review | Low-lying areas near creeks, lakes and the coast |
| Coastal or escarpment setting | Views, landscape and soil stability are assessed | Coastal strips and slopes |
| Plans that miss a Housing Code number | Anything outside the fixed rules needs assessment | Smaller or oddly shaped lots |
| Zone not covered by the Housing Code | The fast lane isn’t available | Some rural and special zones |
One more thing. Shellharbour’s DA checklist also flags items like owner’s consent and, in some cases, Aboriginal cultural heritage due diligence. A DA isn’t just drawings and a cheque. Good prep saves you weeks.
Wollongong approves heaps of “alterations and additions” through the DA route every week, which tells you it’s a normal, well-worn path and nothing to dread. Kiama is smaller, with a bigger focus on heritage and coast, so check early if you’re near the old town centre or the water.
DA vs CDC: which one will your extension need?
Side by side, the two pathways feel very different. Here’s the plain-English version.
| Complying development (CDC) | Development application (DA) | |
| How it’s judged | Tick-box against fixed rules | Merit assessment by council planners |
| Flexibility | None. Every rule must be met | Some room to explain and adjust |
| Neighbour notification | Neighbours are told, but there’s no formal say | Often notified, and they can comment |
| Speed | Usually quicker | Usually slower |
| Best for | Simple, standard-looking extensions on straightforward blocks | Unusual designs, tricky sites, heritage, bushfire or flood |
| Who decides | Council or a private certifier | Council |
A good rule of thumb? If your design is tidy and your site is plain, aim for a CDC. If your site has a quirk, or you want something a bit bolder, a DA gives you room to make your case.
To work out where you sit, try these steps in order:
- Find your zone and lot size. Your council’s online planning tools or the NSW Planning Portal will show it.
- Check for flags. Heritage, bushfire, flood, easements, or a coastal or escarpment setting.
- Compare your plans to the Housing Code numbers. Height, floor area, setbacks, landscaping and privacy.
- Talk to your council or a certifier. Ask them to confirm the pathway before you spend money on final drawings.
- Get a builder involved early. They’ll spot problems on paper that you’d only find on site.
And please, don’t skip step four. A 20-minute chat can save a 20-week detour.
FAQs: council approval for an extension
Do I need council approval to extend my house in Wollongong? Not always. Many standard extensions can go through a complying development certificate if they meet the Housing Code. If your plans or site don’t fit, you’ll lodge a DA with Wollongong City Council.
Is the process different in Shellharbour? The NSW rules are the same statewide, but each council has its own local plan and checklists. Shellharbour’s plan puts a strong focus on the escarpment, Lake Illawarra, the coast and heritage, so those features matter for your site.
What about Kiama? Kiama follows the same state framework. It’s a smaller council with notable heritage, so it pays to check early if you’re near older streets or the coast.
Can a private certifier approve my extension instead of council? For a CDC, yes. An accredited certifier can issue it. A DA is always decided by council.
What if my extension doesn’t meet the Housing Code? Then you lodge a DA. It’s not a failure. It simply means your plans get assessed on their merits.
Do I need other approvals as well? Possibly. A BASIX certificate is common, and you’ll need building approval and inspections as the work goes ahead. Your builder or certifier can map this out.
Who is responsible if I build without the right approval? You are, as the owner. Unapproved work can cause trouble when you sell, insure or finance the property, so it’s worth getting right.
Ready to plan your extension? Start with the right approval
Here’s the quick recap. Council approval for an extension isn’t a single yes-or-no. Small jobs may be exempt. Neat, standard extensions can often use a fast complying development certificate. Anything that breaks a rule, or sits on a block with heritage, bushfire, flood, coastal or escarpment flags, usually needs a DA.
Around Wollongong, Shellharbour and Kiama, the land itself has a lot to say about your project. That’s why the smartest first move is a quick check of your zone, your lot and your site constraints, before you fall in love with a floor plan.
At Modern View Constructions Pty Ltd, we help Illawarra homeowners work out the right approval path early, so the build runs smoothly from day one. Got an extension in mind? Get in touch for a friendly chat about your plans, your block and what approval you’re likely to need.
Planning rules change and every property is different. Treat this guide as general information, and confirm the details with your council or a certifier.