The Reserve Bank says changes to Debt-to-Income and Loan-to-Value Ratio restrictions will help, long-term

It'll change the amount banks can lend in relation to a borrower's income.

Most new owner occupiers won't be able to borrow more than six times their pre-tax income - and investors no more than seven times.

Deputy Bank Governor, Christian Hawkesby, says it'll help us avoid the big boom-bust cycles previously seen.

He says it's about getting the tools in place during calm times, for when they may need in the future.