Are bathroom exhaust ducts checked during final inspection? (Bathroom | Building & Approvals)

Are bathroom exhaust ducts checked during final inspection?
Short answer: absolutely yes — and inspectors take this part surprisingly seriously.

During a bathroom renovation, the exhaust system isn’t just a “nice to have”; it’s a mandatory feature under Australian building standards. By the time the certifier arrives for final inspection, they want to see that the exhaust duct is correctly installed, correctly routed, and actually doing its job. Think of it like the bathroom’s lungs — if they’re blocked, the whole room gets sick.

What do they look for?
First, the certifier checks that the fan vents to the outside, not into the roof cavity. This is one of the most common renovation mistakes, and it causes mould faster than a forgotten lunchbox in summer. They may also check the size and rating of the fan to make sure it matches the bathroom’s volume. A tiny fan in a big bathroom is like trying to dry a dog with a hand-held fan — it’s just not happening.

Second, they make sure the ducting is sealed properly. Gaps and loose joints let steam escape into places it shouldn’t, and inspectors aren’t shy about sending you back to fix it if something looks dodgy. They may also check that the duct is as straight as possible, with minimal bends to keep airflow strong.

If you’ve added a new bathroom, or made structural changes requiring approval, the exhaust system is part of the compliance checklist. Even if the renovation looks amazing — shiny tiles, designer vanity, fancy fittings — a bad exhaust setup can fail your inspection in two seconds. It’s like wearing an expensive suit but forgetting the socks.

For homeowners, the good news is that when the exhaust duct is installed correctly, it protects your bathroom long-term: less condensation, less mould, longer-lasting paint, and fewer maintenance issues. And yes, inspectors love bathrooms that behave themselves.

If you’re planning a bathroom renovation and want the approval process to be smooth, make sure your exhaust system is designed and installed properly from day one. Curious to learn more or planning your own renovation journey? Visit www.mb9.com.au to find out more about kitchen, bathroom and laundry renovation services from MB9 Australia Pty Ltd.