Australia's housing downturn is hitting the top end of the market hardest, with upper-quartile house values in Sydney and Melbourne now more than 10% below their peaks, while lower-priced homes and units remain comparatively resilient, Cotality said in a Thursday report.

The downturn has spread beyond Sydney, Melbourne, and Canberra, with property values now falling in Brisbane, Adelaide, and Perth, while higher-value homes continue to experience the sharpest declines, said Gerard Burg, Cotality head of research.

The gap in house price declines between the upper and lower quartiles is widest in Melbourne at 6.6 percentage points and Sydney at 5.3 points, compared with less than one percentage point in Brisbane, Adelaide and Perth, per the report.

Units have generally remained more resilient due to their relative affordability, with Melbourne and Sydney recording the largest gaps between value segments at 4.9 and 4.5 percentage points, respectively.

Canberra was an exception, with lower-quartile unit values falling 2.9% from their peak, compared with a 1.6% decline for upper-quartile units, while Perth units underperformed houses across all value segments.

Broader market indicators suggest worsening selling conditions, with national annual sales falling 2.7% in the year to August, driven by a 5.2% decline in capital cities, while regional sales increased 1.8%.

The median time on market rose to 39 days from 28 days a year earlier, while the median vendor discount across capital cities widened to 4.2%, its highest level since January 2023.

Total listings rose over 18% year-on-year to more than 139,100 properties, 2.2% above the five-year average, while the four-week average auction clearance rate stood at nearly 50% at the end of August and has remained below 50% since early June.