Sydney's property market slump will last at least another two years as tougher lending standards and buyer nerves weigh on prices.

That's the consensus from a Bloomberg survey of 15 economists, over a third of which have turned more pessimistic within the last three months.

Sydney house prices are tipped to continue slumping. Credit:Peter Braig

Prices Australia-wide have fallen for nine straight months as the housing boom goes into reverse. Sydney, where affordability is most stretched and investors had the biggest influence, is being hit hardest: values in the harbour city are down 4.5 per cent in the past year compared to 0.8 per cent nationally.

"Sydney is at the epicentre of the housing market downturn," said Stephen Roberts, an economist at Laminar Capital.