The apartment building boom is rolling on despite warnings of an overheated market according to the number of cranes on the skyline.

Where once most were on commercial projects, property and construction group Rider Levett Bucknall's (RLB) Crane Index for the second quarter found that the lion's share  are now towering over housing sites.

This trend is expected to continue as more large-scale non-residential developments are completed, such as Barangaroo South in Sydney, Southgate, Melbourne and the Commonwealth Games venues on the Gold Coast.

While the total number has slipped from the record 666 a year ago, there were still 330 new tower cranes erected across Australia's skylines in the past six months, offset by the removal of 342 cranes from projects nearing completion.

The residential sector continues to be dominant with 548 cranes, representing 84 per cent of all cranes commissioned on future dwellings. The sector saw a net gain in crane numbers of nine since the last index. 

The only other sectors to show growth in crane numbers were the health (hospitals), retail (new shopping centres) and civil sectors, (government and infrastructure) with three, one and three additional cranes respectively.

This correlates with the latest government figures showing dwelling starts (commencements) rose 0.3 per cent in the December quarter after a flat result in the September quarter. House approvals fell 3.4 per cent, but apartments rose 3.9 per cent.

According to the RLB index, Sydney remains the hottest construction market with the greatest number of cranes erected in the residential (292), commercial (13), civil (7) and civic (6) sectors. The spread of cranes showcase the construction activity along the main northern, western and southern corridors of Sydney.

The current boom in crane numbers even overshadows the feverish construction in the years before the Sydney Olympics in 2000. In 1998, for example, there were 34 cranes across the Sydney CBD while at Olympic Park there were 35 working at what is now ANZ Stadium.

Melbourne dominated the education sector (4) and retail sector (2). Construction work in Victoria was up 6 per cent in 2016. Residential work is still strong recording a 10 per cent lift, while non-residential work was down 8 per cent.

Stephen Ballesty, RLB director of research & development said as residential prices across the country continue to rise, development activity across Sydney and Melbourne are fuelling much of the national growth numbers.

"General economic activity across the states has turned in recent years, with both NSW and Victoria leading the charge as Western Australia, Queensland and Northern Territory are feeling the effects of the post-construction phase of the mining boom," he said.

"Sydney continues to be the driver of crane activity within the country with 50 per cent of the nation's cranes, up from 46 per cent at our last RLB Crane Index, followed by Melbourne with 22 per cent and Brisbane 12 per cent."

State by State

Across Melbourne, the CBD and surrounding suburbs have 43, or 30 per cent of cranes were installed. The eastern suburbs have 28 (19 per cent), the north 30 (20 per cent), the south 35 (24 per cent) and the west 10 (7 per cent) cranes installed.

Perth's RLB Crane Index fell 50 per cent, reflecting the completion of 16 projects that saw the total crane numbers in Perth fall by 24 cranes.

In Brisbane three new commercial cranes commenced and three were removed. Two cranes were removed from 1 William Street and one from Benson Street, Toowong. New commercial projects include 900 Anne Street and two cranes have been installed at St Pauls Terrace.

Has the building boom found its peak? Perhaps, but the data is volatile on a monthly and quarterly basis," Craig James, chief economist at ComSec said.

"There are certainly signs that the construction boom is peaking. Still, there is a near record amount of homes currently being built and that is going to provide work for a lot of people for the next few years."