New Zealand residential property prices rose in March, led by Auckland where housing supply isn't meeting demand, putting pressure on the market.

Auckland's median house price jumped 13 percent to $720,000 in March, compared with the year-earlier month, outstripping an 8 percent rise in the national median price over the same period to $475,000, the Real Estate Institute said in a statement. Excluding Auckland, the national median price increased 1.4 percent to $350,000 compared with the year earlier, unchanged from February, the agency said.

"The movement in the national median price is almost entirely an Auckland effect," said REINZ chief executive Colleen Milne. "The underlying demand pressures remain and supply continues to be restrained by low numbers of new listings."

The Reserve Bank estimates Auckland has a shortfall of between 15,000 and 20,000 properties to meet population growth as the country experiences record migration. The bank, which is constrained from cutting interest rates because of concern it would further stimulate the housing market, is considering new restrictions for residential property investors amid concerns that rising house prices may pose a risk to financial stability. RBNZ deputy governor Grant Spencer may provide an update on the bank's thinking in a speech about housing to the Rotorua Chamber of Commerce tomorrow.

Some 8,803 residential properties were sold in March, 20 percent ahead of the year earlier and the highest level since 2007, REINZ said.

Auckland March sales volumes increased 21 percent from the year earlier month and were 56 percent ahead of February, the agency said. Auckland had a record number of auction sales in March, accounting for 78 percent of sales, and had a spike in the number of house sales worth more than $1 million, which helped push up Auckland median prices, it said.

Houses took a median 32 days to sell last month, one day fewer than March last year.

The REINZ stratified housing price index, which strips out variations in the mix of high and low-values homes sold, rose 9.5 percent to a record 4,340.9. The Auckland index gained 20 percent to a record, the Christchurch index rose 5 percent and the Wellington index advanced 3.8 percent.