Building permits data can be 'lumpy', with multi-unit approvals varying month to month.
But there's lumpy and there's this. Minus 27 odd per cent is a huge slump in a month, cushioned somewhat by the +18 % the previous month.
Permits have been on a downward slope as the Reserve Bank of Australia have hiked rates, making development more expensive, at the margin. Along with all the other inflation-driven surging costs to builders.