The Reserve Bank has signalled it might extend tougher lending limits to property investors outside Auckland, who would then need to have a deposit of at least 30 percent.
The central bank's deputy governor, Grant Spencer, said the expanded limit could be in force by the end of the year, although he stopped short of saying it would be imposed.
He said the central bank would consult with trading banks on debt-to-income limits, which would also need the approval of the government, and would also look at the amount of money banks needed to back their lending.
Mr Spencer made the comments speaking to the Wellington Branch of the New Zealand Institute of Valuers this evening.
A range of factors had contributed to strong demand for housing, including record low interest rates, rising credit growth and population increases, he said.
At present, the Reserve Bank's measures are limited to Auckland property investors, who cannot borrow more than 70 percent of the value of a property.
Mr Spencer's speech comes amid growing expections that the central bank needs to take extra steps to cool the country's surging housing market.
However, the Property Investors' Federation said there had always been challenges for first-home buyers, from high interest rates in the past to high deposits now.
Its executive officer, Andrew King, told Checkpoint with John Campbell the answer wasn't to crack down on investors, who were providing more options in the rental market.
Mr King said higher lending limits would mean rents would go up, and that would make it even tougher for people trying to save up for a deposit.