Okay, so I’ve been lurking in this sub for about two years, reading every granny flat thread I could find. Finally went ahead and did it. Build is complete, tenant is in, and I figured I’d write up what I actually learned versus what I expected going in.
Quick background: 700sqm block in the Illawarra region. The existing 3-bedroom house that we live in. Always wanted to do something with the back section of the block, but never quite got around to it.
Why we finally did it
Honestly? The rental market out here is really strong right now. Good, reliable tenants are actively looking for quality places to live in the region. That made the decision feel a lot more straightforward than I expected.
Also, we’re not getting younger. The idea of having mortgage-helping income without buying another property felt… actually manageable for once.
The planning stage was smoother than I expected
I’d heard it could take a while to get approvals sorted. And yes, it takes some time. But if your property meets the basic criteria for a compliant secondary dwelling, block size, setbacks, and height limits, the Complying Development pathway means you’re not going through a full DA. That saved us probably four months.
The granny flat builders Illawarra team we ended up going with walked us through this on the first call. Didn’t try to make it sound complicated. Just explained it plainly. That was a good sign early on.
What the build was actually like
We got three quotes. Range was pretty wide, about $40k between the lowest and highest for essentially the same spec. We didn’t go with the cheapest. We went with the one whose previous clients actually returned our calls when we asked for references. Wild concept, I know.
Build took about fourteen weeks from slab to handover. There were two short weather delays and a brief pause while a subcontractor sorted their schedule. Pretty standard from what I’ve heard.
The stuff worth knowing ahead of time
Utilities deserve more attention than people give them early on. Connecting water and electricity, and getting a separate meter sorted, involves a fair bit of coordination. Start this process earlier than you think you need to. Your builder should flag this for you, but it’s worth asking about it specifically in your first meeting.
Also, finding a tenant was genuinely easy. Listed on a Friday, had strong enquiries by the weekend, tenant signed the following Thursday. The demand for quality rentals in this region is very real.
Numbers for the nosy
Build cost all in: $158,000. Weekly rent: $460. Annual gross: $23,920. We’re really happy with that. Not retiring tomorrow, but it takes a meaningful chunk off the mortgage every month, and that’s exactly what we needed.
Would I do it again?
Without hesitation. The process was smoother than I’d expected. The key was finding people who’d done it many times before and had a clear system for every stage.
Happy to answer questions in the comments. These threads were incredibly useful when I was in research mode, so just paying it forward.
