In short:

Quarterly data show the median house price has gone down in every capital city for the first time in 15 years.

The trend varies outside the capital cities, with Vic, NT, and SA all seeing regional prices rise.

What's next?

A real estate agent in regional SA, where the increases have been steepest, has seen inquiries plummet in the last few weeks.

Australia's last holdout against a cooling house market is still on the way up, but years of rapid growth are expected to come to an end soon.

Earlier this year Helen Burns sold her "little cottage" in the Adelaide Hills for about $800,000, venturing 350 kilometres south-east to a new home in the small town of Penola in South Australia's South East.

The move was motivated by family factors but deemed a "no-brainer" when she crunched the numbers.

"[I] pretty much tripled the land size and doubled the house size for only $20,000 [more]," Ms Burns said.

This kind of calculation saw regional prices rise in Victoria, the Northern Territory and South Australia, with regional SA the steepest of the bunch.

On the ground in the lagging state

The latest Domain property report showed prices outside of Adelaide rose 19 per cent in the past 12 months, with the median price at $595,000.

A report from Proptrack earlier this year outlined how regional SA house prices had almost doubled in the past five years.

Naracoorte real estate agent Margot Shortt described the past year as "nothing short of crazy" with many people getting into the market thinking it would keep rising.

While prices have continued to rise, Domain's data only runs to September 30; and two days earlier, the RBA lifted interest rates to a 15-year high.

Ms Shortt said this, along with broader economic factors, meant calls and messages to the agency had "absolutely fallen off a cliff".

"We have seen probably a 99 per cent decline in enquiries."

She said it was hard to actually know if the local market was dropping given the lack of recent sales.

"Is the market terrible? We haven't really seen too many transactions transpire so we can't compare," she said.

All capital cities down

The latest Domain property report showed Australia's housing market fell 4.7 per cent, the steepest quarterly drop on record.

Every capital city has seen the median house price head south for the first time in 15 years.

But outside the capitals, data were more varied.

Adelaide University housing economist Chris Leishman said Sydney and Melbourne were generally the first to witness shifts and Adelaide was "always a fairly slower responder".

He said you would expect regional SA to be the last housing market still growing as the rest of the country started to plateau or drop.

"Look at any state and compare it to its metropolitan city … the regional areas tend to perform strongly later in the cycle," he said.

Professor Leishman said Australia is at the tail end of one of the longest and most pronounced housing booms ever seen.

Across Australia, he failed to see strong growth over the next couple of years and believed there "has to be a correction".

"Markets tend not to crash though, particularly in Australia,"he said.

He expected six to 12 months of prices going down further, before starting to rise again in the long term.