A typical house in Auckland now costs 10 times the median household income.

That's Labour's latest housing horror story - the party says the internationally accepted affordability benchmark is three times median household income making a mortgage longer to pay off.

"If any further proof was needed, this is it. Auckland is now officially off the scale," housing spokesman Phil Twyford said on Tuesday.

"It now takes about 50 years to pay off the average Auckland home."

Mr Twyford's figures come from a Barfoot and Thompson report which put the median house sale price in June at $NZ786,000 ($A701,400), and Statistics NZ's median household income of $NZ78,600.

Labour blames the government for Auckland's housing shortage, the main reason for rocketing prices.