New Zealand residential property values rose at the fastest quarterly rate in 12 years, with the national average value of a house now topping $600,000.

That’s a 6.1 per cent in the three months through July to $602,434, marking the fastest quarterly gain since December 2003’s 6.8 per cent pace, according to state-owned valuer Quotable Value. For the month of July, the average value jumped 14.1 per cent from the same month a year earlier,…