You’ll need your occupancy certificate. Your builder wIll know the conditions or you can call your local council as they’re the issuer, with the builder the requestor.

There is some info in this link for Victoria.

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiOxqLiqJL-AhWL8TgGHT3RD2wQFnoECAIQAw&url=https://www.vba.vic.gov.au/consumers/home-renovation-essentials/end-of-project&usg=AOvVaw3zQXU9eZ6H3UegUz4gugRF

If in Western Australia, it is the same. You can not occupy a building until a occupancy certificate is issued. This is part of the regulations and paperwork that your builder should take care of. As bigreader has said, consult your builder, and discuss your situation. If an owner builder, it is the same regulations. An occupancy certificate must be issued. It is an offence to occupy a building without it. The certificate covers health and safety, planning permission, water regulations.

what we can live without by moving into an unfinished house is not the same as what's legal and usually you can't move in without the builder (and their insurer and your bank) releasing the property to you and for that to happen you need the final council inspection certificate that confirms that there is a functioning kitchen, bathroom and laundry and anything else agreed to in the Development Application... in a similar situation, we installed a temporary "kitchen" using a few second hand cabinets, a sink with functioning taps and a cheap upright stove and were given approval to move in months before our permanent kitchen but, our new kitchen wasn't part of the builders' contract and your builder and bank may not agree to allow you to move in as that would waive the builders' insurance and complicate release of final payments ... i suggest that you discuss with your builder, insurer, bank and local building inspector as they have the final say about when they can release ownership of the home to you but maybe they could allow you to use finished rooms for storage as long as that doesn't compromise insurance or access to finish their work and you include your own suitable insurance.....it's complicated

Hmmm, thanks all. I didn’t even think about the legal side of things. I’ll call our private certifier tomorrow. If they sign off before permanent kitchen is in (we have lots of space upstairs to put a fridge, portable stove etc etc and actually still have some of the old kitchen cupboards we could use) will having the water connected be an issue? Just wondering when that is usually connected in a normal build? Also hate using the portoloo when I’m onsite so really want water conntected. So gross! Also curious when people don’t move out during an extensive reno how the occupancy certificate works? It’s really go me thinking now…

A renovation doesn’t usually require an Occupancy certificate as the original structure would have had one. It is a bit dodgy though with room to bend the rules for a renovation- I’ve lived with a microwave and a fridge and no kitchen, have also lived (before kids) without a bathroom but did have a toilet.

a functioning kitchen, bathroom and laundry means water is connected

Also our bank gave us the lum sum to manage so releasing money shouldn’t be an issue and is cost plus with the builder so he said he doesn’t have an issue with us moving in early except it would slow him down a bit. Insurance might be a big issue though?

More information for you. https://build.com.au/practical-completion-and-certificates-occupancy

Just a thought -- if you know someone with a mobile home or similar , especially if they aren't going to use it , maybe see if you can do a deal to rent it , and sit it on site . You could even let them have the keys for the motor , so they know its not going to use anything like fuel or wear and tear on engine , tyres , etc . That might get around most of the legal requirements ?

Sounds like you're making steady progress with the tiling and flooring! When it comes to plumbing and water, it's usually a bit tricky. Running toilets and showers definitely make life more comfy. As for the kitchen, living without it for a bit could be doable if you're up for a little creativity (camping-style meals, anyone?).

And speaking of navigating through housing situations, have you considered connecting with a Mortgage Broker in Bridgend? They're like the experts who can guide you through all things mortgage-related.