Skyscraper construction is at all-time high, with 78 tall buildings completed across the globe already in 2014.
According to data from the Council on Tall Buildings and Urban Habitat (CTBUH), Australia is home to 11 of these completed projects, with 35 more tall buildings scheduled to be completed in the country by the end of 2014.
Urbanisation is bringing about a sky-high built environment in order to intensify cities and house a growing population.
Today, architects and developers are under increased pressure to deliver buildings that respond to urban demand while being environmentally sound.
Skyscrapers combat urban sprawl, and many are of the mixed use variety, offering residential units, commercial and retail spaces and in some cases, educational/vertical urban campuses.
Last month, Kingdom Tower in Saudi Arabia broke ground. The ambitious skyscraper is tipped to break the one kilometre height mark, a feat matched when China announced two one-kilometre tall towers that would be completed a year earlier than Kingdom Tower and which would actively combat pollution.
Earlier this year, skinny skyscrapers were forecast to be the most popular architectural design for tall buildings, a trend CTBUH editor Daniel Safarik, CTBUH says still stands.
"In certain markets, such as New York, Vancouver and Hong Kong, the impetus to build skinny continues - a lack of build able land and the high premium for views continues to dictate this," he said.
New York has drawn the most attention for its skinny skyscrapers. Rafael Vinoly's 432 Park Avenue will reach 425 metres with a small footprint of 8,250 square feet, while SHoP's nerby 111 West 57th Street will be a striking addition to the skyline, rising 411 metres at a width of a mere 13 metres, giving it a width-to-height ration of approximately 1:30.
Even smaller in width is a recently approved skinny skyscraper in Melbourne at 54-56 Clarke Street, Southbank. The 240-metre building will be around 12 metres wide at its narrowest point and its architects Black Kosloff Knott have designed the tower to twist slightly as it rises to maximise natural light within the building.
Safarik said architects are challenging the traditional rectangular-tower skyscraper design, creating buildings which are not necessarily super-tall but which offer cylindrical, abstract and/or clever twisting forms.
"The successful completion of projects such as Guangzhou Circle, Sheraton Huzhou Hot Springs Resort, Cayan Tower etc. will likely encourage others to pursue non-conventional shapes," he said. "But the skinny trend is the most easily identifiable and most likely to spread to other cities."
Joseph di Pasquale, the Italian architect behind Guangzhou Circle, said earlier this year that skyscrapers will be recognised less for their height than for their iconic value. He believes skyscraper heights will eventually be limited by materials and costs, creating an opportunity for architects to create something that could be a landmark for the city.
Conventional materials continue to reign in skyscraper construction - particularly concrete.
"We're still mostly using concrete and steel," Safarik said. "…although there are many novel combinations of the above, such as concrete-encased steel columns and beams, that are proving to be useful in helping achieve stability and planning flexibility in tall buildings."
"We're also seeing more use of high-strength concrete, which ultimately means less environmental waste and a thinner allowable thickness, which means more floors for the same amount of concrete."
The other hot topic remains around the potential for wooden skyscrapers - or "woodscrapers" - which are gaining interest for their carbon sequestering qualities.
Safarik referred to projects in Scandinavia and Canada, where large timber industries allow developers to bring tall wooden buildings out of the prototype phase and into use.
Last year, Berg | C.F. Møller Architects proposed a 34-storey wooden skyscraper for Stockholm, noting wood's sustainability, strength, fire resistance and acoustic benefits in the built environment.
In Australia, the Forté apartment building in Docklands, Melbourne holds the title of the world's tallest timber building at 10 storeys, but a new 14-storey woodscraper is currently under construction in Norway. Forté features 760 panels of certified and manufactured cross-laminated timber.
Despite these projects, obstacles still surround the construction of wooden skyscraper, with Safarik citing local fire codes as a primary challenge.
"Many jurisdictions do not have testing standards in place for how to make heavy timber or cross-laminated timber (CLT) acceptable under fire code (although it certainly can be rendered to the same safety standards as concrete, and outperforms steel in some cases)," he said. "Also, the wood-products industry has not come up with an "assembly-line" mass production of CLT's that would be needed to make a preferred building for most tall buildings."
Safarik adds that it is encouraging that the White House Rural Council and the United States Department of Agriculture recently announced a climate-driven initiative that would fund research and training into "tall wood" in a bid to accelerate adoption and increase practical heights.
"Wood may be one of the world's oldest building materials, but is now also one of the most advanced, said Agriculture Secretary Tom Vilsack at the time of the announcement.
A second installment in this two-part series on the skyscraper trend forecast, covering purpose and sustainability, will be published in the coming days.