"Sydney's housing market has become the most significant drag on headline growth figures", he said.
While that would be in stark contrast to the performance seen in recent years, Oliver says low interest rates and support for first home buyers will provide "some support and should help ensure only moderate price falls".
Melbourne home values fell by 0.2 percent in December, the first monthly drop since February 2016, paring the quarterly gain to 0.9 percent, the data show.
Prices in Australia's largest and most expensive housing market fell 0.9% in December, leaving the decline over the past three months at 2.1%.
'We're likely to see lower to negative growth rates across previously strong markets, more cautious buyers, and ongoing regulator vigilance of credit standards and investor activity'.
"The substantial fall in values relative to rents has pushed Darwin rental yields to their highest level since July 2015", Mr Lawless said.
Darwin's rental yields are 5.9 per cent, making it the highest out of all capital cities.
The lacklustre results were expected to continue for both cities over 2018, which was "likely to be significantly different" to the boom cycle of the past few years, Mr Lawless said.
"Melbourne's annual rate of capital gain, at 8.9 per cent, has fallen below double digits for the first time in 11 months."
Its affordability, compared to other capital cities, was the main reason for capital appreciation in the Tasmanian capital's housing market.
The median in Sydney now $1,058,306, and $832,735 in Melbourne. Adelaide and Canberra grew 0.2 per cent, while Hobart grew 1.2 per cent growth.
Darwin and Perth were the worst performing markets a year ago, with property prices falling annually by 6.5 per cent and 2.3 per cent respectively.
As for its property forecast, CoreLogic has warned prospective buyers to expect "softer housing market conditions through 2018, driven by a continuation of the slowdown that is clearly evidence across Sydney and to a less extent, Melbourne".