About a year ago, school teacher Brendan Deith noticed there was a hole in his budget. The 40-year-old Melburnian had done $400,000 worth of renovations to the house he shares with his wife Beck and two daughters in 2021, and slowly but surely rising interest rates were beginning to hurt.

His concern was that with further rate rises the family’s $700 a month surplus would degenerate into situation where they were $1500 in the red. “We knew we had to come up with a plan,” Deith says. He’d been using a budgeting app to track the family’s finances since 2018 and knew they’d previously had a much healthier $2000 surplus.