Mr Bolton, a former general manager at ANZ National Bank, said most clients could meet the extra cost of repayments if they put their mind to it.
"When rates eventually rise they'll need to pay [7.5 per cent] anyway, so why not do it now and pay the mortgage off faster?"
He said the average first-home owner with a $400,000 loan could be mortgage-free after 12 years.
That would require paying a repayment rate based on 7.5 per cent interest and giving up half of any pay increases to the mortgage.
"Over time inflation does its job in reducing the 'real' cost of a mortgage. It becomes a lower proportion of real income as salaries increase."
Claire Matthews, of Massey University's banking studies department, said interest rate savings should go straight into repayments.
"There hasn't been a lot of movement in terms of interest rates for some time ... All of a sudden things are changing, so people are taking notice.
"Unless you absolutely have to, don't change your repayments ... It can have a huge impact in terms of the total length of your loan."