A new survey shows that Australia's two biggest cities continue to rank among the least affordable on the planet with respect to real estate prices.

The 2014 Demographia International Housing Affordability Survey puts Sydney and Melbourne in fourth and sixth position respectively on its list of the least affordable cities in the world.

Densely populated Hong Kong was deemed the most expensive metropolis, while Vancouver and San Francisco came in second and third place. Rounding out the rest of the top 10 list were San Jose in fifth place, Auckland in seventh place, and San Diego, Los Angeles and London in the eighth, ninth and tenth positions respectively.

The highly comprehensive Demographia survey examined a total of 360 cities in nine industrialized nations, including Australia, Canada, Hong Kong, Ireland, Japan, New Zealand Singapore, the UK and the US. Cities were placed in one of four categories – severely unaffordable, seriously unaffordable, moderately affordable and affordable; by means of median multiple evaluation, which is the same method employed by the World Bank and United Nations for their assessment processes.

Australia, New Zealand and Hong Kong were all categorized as “severely unaffordable,” with analysts having long issued warnings about the formation of bubbles in these markets as a result of low interest rates and the keen appetites of cash-flush investors from China.

Despite its modest population size and comparatively large area, Australia also lays claim to the greatest number of “severely unaffordable” housing markets, boasting 25 in total. The US took second place in this respect with 23 such markets, while the UK came in third with 15.

The study also points out that each of Australia’s major markets enjoys the dubious distinction of having remained “severely unaffordable” for all 10 years of the survey. Only one other market in the survey shares has achieved this – New Zealand’s most populous city, Auckland.

The authors of the survey point to restrictive land use policies as the one factor shared in common by all of the housing markets in the “severely unaffordable” category.

Urban planner and New York University research scholar Alain Bertaud wrote in the introduction to the report that planners may have to abandon luxuries such as liveability and sustainability if they want their cities to remain affordable for  local resident.