Dwelling values in Australia's cities have fallen for the first time in 17 months, according to new data.

RP Data-Rismark figures for June reveal that the seasonally-adjusted value of city housing fell by 0.7% during the month, and by 0.2% over the June quarter. RP Data comments that this is the largest monthly fall in home values since April 2008, and continues a clear trend of declining growth rates since February.

In terms of individual cities, the picture is mixed: Sydney, Melbourne and Adelaide all recorded mild increases in growth (0.5%, 0.2% and 1.1% respectively) while values in all other capitals fell. Perth recorded the largest fall in value over June at -2.5%.

'Rest-of-state' figures for the nation showed an increase of 0.3% (seasonally-adjusted) in the June quarter. National average dwelling prices stand at $465,000 in cities and $415,000 nationally.

"We’ve been forecasting a substantial deceleration in housing conditions back to single-digit annualised growth rates since October 2009," said Rismark's managing director, Christopher Joye. "We do not expect to see the market rise much more over the remaining year subject to labour market conditions and the course of monetary policy."

Joye cautioned that the falls in value were no reason to panic, however.

"It’s sobering to remember here that we have had 17 consecutive monthly increases in Australian capital city home values," he continued. "If the sharemarket rose for 17 months straight and then tapered, people would not think twice. It might be wise to apply the same logic to our housing market."

RP Data's Head of Research, Tim Lawless, concurred, adding that while the inventory of unsold homes has increased of late, he expects new listings activity to slow in the coming months. Average time on market and vendor discounting also remain in line with "historically reasonable levels", he added.