The top end turned first. Now agents need to watch what follows

Australia's premium housing market gave the first warning that conditions were changing.

The question for agents now is how far that weakness travels.

Cotality's September Housing Chart Pack shows upper-quartile house values are now 10.7 per cent below their peak in Sydney and 10.5 per cent below peak in Melbourne, making the most expensive end of those markets the clearest casualty of the current downturn.

But the sequence is becoming more significant than the size of those two falls.

Earlier in the cycle, declining values were concentrated largely in higher-priced parts of Sydney, Melbourne and Canberra.

More recently, falls have extended into Brisbane, Adelaide and Perth, while Cotality's suburb-level analysis found 93 per cent of capital-city suburbs recorded a decline through winter.

Lower-priced housing remains more resilient than prestige property in most capitals, so this is not a case of every segment suddenly falling at the same rate.

It is, however, a signal that the insulation enjoyed by more affordable property is becoming thinner.

That matters on the ground.

National homes are now taking a median 39 days to sell, compared with 28 days a year earlier. Capital-city vendor discounting has widened to 4.2 per cent and total listings are more than 18 per cent higher than a year ago. The four-week average auction clearance rate finished August at 49.5 per cent.

For agents, those measures arguably tell a more useful story than a national median.

They determine the conversations happening in lounge rooms now: how recent a comparable sale should be, how much weight should be given to a result from six months ago, whether a vendor's original expectation is still realistic and how quickly a campaign needs to respond when buyers do not.

The premium market turned first because higher-priced housing has generally been more exposed to borrowing constraints and changing demand.

The later spread across cities and price bands suggests the downturn is progressing in stages rather than arriving everywhere at once.

That creates a practical advantage for agents paying attention to the sequence.

The top end has already shown what softer conditions can look like.

The rest of the market now has a warning.