More Canberra houses are selling at a loss on the real estate market, particularly after short ownership periods, according to a new report.

A CoreLogic RP Data Pain and Gain report found more than 12 per cent of ACT homes sold below their previous purchase price in the September quarter.

The number of loss-making sales in Canberra has risen consistently over the past year, while losses in most other capital cities have fallen.

The report's authors noted that nationally houses sold after less than six years ownership were more likely to suffer a loss.

"For resales incurring a gross loss over the September quarter, the average length of ownership was just 5.7 years," analyst Cameron Kusher said.

"Properties that recorded a gross profit were held for an average of 9.9 years, while those homes that resold for more than double the previous purchase price were owned for an average of 16.8 years."

The report also found the median loss in Canberra was just over $18,000 in the quarter, after an average ownership of four years.

On the upside, householders who sold for a profit made a median $144,000 after an average ownership period of nearly 10 years.

Previous economic reports have predicted public service job cuts and increased apartment releases would push down Canberra real estate prices over the long term.

Nationally, the September 2014 quarter results confirmed that 9.3 per cent of all home resales recorded a gross loss compared to their previous purchase price.

That is a slight increase from 9 per cent recorded over the June 2014 quarter, but lower than the 11 per cent recorded over the September 2013 quarter.

Mr Kusher also noted that unit dwellings within lifestyle markets were generally showing the largest proportion of loss-making resales.