when will see a fall of house prices in au

It's happening in US, UK and NZ - when will it happen here? The house price bubble doesn't last forever.

Decline in home prices accelerates in March

WASHINGTON (MarketWatch) -- Home prices in 20 major U.S. metropolitan areas have dropped a record 14.4% in the past year, Standard & Poor's said Tuesday.
The 20-city Case-Shiller home price index fell 2.2% from February to March. This is the 16th consecutive decline in prices.
And for 10 major cities, prices fell by 2.4% in March and by 15.3% for the past 12 months.
S&P's Case-Shiller index tracks sales of the same homes over time, so it's not influenced by the mix of homes sold in a period. However, it closely tracks only 20 cities, many of which had participated in the housing bubble earlier in the decade.
A separate index released last week by the Office of Federal Housing Enterprise Oversight showed a much smaller 1.7% decline in prices in the first quarter. In the OFHEO index, prices fell 0.4% during March. See full story.
The OFHEO index covers more areas but only includes mortgages that conform with Fannie Mae and Freddie Mac standards.
Falling prices have eroded Americans' wealth.
On Friday, the National Association of Realtors reported that existing home sales fell 1% in April. See full story.
Some economists welcome the drop in prices, saying that the sooner the price declines play out, the quicker that the bottom of the housing market will be reached.
But there's also concern that prices might overshoot on the downside, hurting banks and financial-services firm and hamstringing the economy.
Economists at Lehman Brothers expect national Case Shiller prices to fall an additional 14% to 20%, translating into what would be a peak-to-trough drop of about 25%