Homeowners are being urged to check their insurance policy, to ensure it covers the actual cost of building and repair work.
Construction costs have skyrocketed, with the price of steel and timber up 15 percent - something insurance hasn't caught up with.
A clothing dryer caused one home to go up in flames last month. Its owner Ruby Debs Oakley is devastated.
"The whole back of the house is gone. The front of the house, really bad smoke and water damage," Oakley says.
Her home insurance payout was $400,000. But the actual cost of repairing it is much higher.
"To fix it they got the quote of $520k - another $100k," Oakley says.
She's not the only one with a huge shortfall. Quantity surveyor Andy Thomson says most homeowners won't get a payout big enough to cover the rapidly increasing cost of rebuilding or repairing a property.
"Eighty percent of people are underinsured. They're underinsured by about 50 percent. It's not a small amount, and that's before all this inflation started so it'll just be getting wider," he says.
Most insurers require customers to set the price of a rebuild for their policy and have it revalued every year.
"The insurance company doesn't take that responsibility anymore. If you say it's gonna be a million dollars, and it costs $1.5m, you're only getting a million dollars," Thomson says.
The Insurance Council's chief executive Tim Grafton says "some insurers do offer full replacement for homes in the case of a non-natural disaster" like a fire.
But for that to apply, "customers need to show they've taken all reasonable efforts to get an accurate sum insured".
For example, getting a building report or using an online calculator, that factors in the cost of demolition and consents.
They are things Oakley never thought about. Now she's warning other homeowners to check their cover.
"I'd get an independent quote from a builder or someone independent, the cost of rebuilding or fixing," she says.
In case it ever happens to your home.