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, ahead of June’s 13.5 per cent gain.

The country’s housing market has continued to strengthen, bolstered by record high migration and record low interest rates.

In Auckland, the largest city, where prices have surged due to a shortage of supply, the average value gained 16 per cent over the year to sit just shy of $1 million at $992,207. Hamilton, Queenstown Lakes and Tauranga saw some of the fastest growth, with Hamilton values soaring 31.5 per cent over the past year, twice the pace of Auckland.

“Values continue to rise rapidly in many parts of New Zealand, buoyed by low interest rates, strong investor activity and high net migration,” QV spokesperson Andrea Rush said.

A plan for Auckland housing released last month has proposed the city be more densely populated with a larger urban area and less prescriptive development rules to help spur construction and ease the shortage, and the Reserve Bank has signalled plans to extend loan-to-value ratio restrictions on home loans in an effort to cool the market.

In other main centres, Tauranga values surged 25.7 per cent to an average $615,625 in July from the year earlier. Wellington values increased 15.9 per cent to $633,611, Dunedin city rose 11.1 per cent to $331,967, and Christchurch gained a more modest 3.5 per cent to $492,165.

Among other large gains, values in the Queenstown Lakes district soared 27 per cent to $910,974, Waikato jumped 27.5 per cent to $389,220, Kawerau surged 41 per cent to $143,765, Otorohanga district rose 29 per cent to $250,202 and Rotorua increased 24.8 per cent to $338,679.