In an artist's rendition, the Pearl River Tower soars above the Guangzhou skyline looking like a cross between a flattened rocket ship and a cellphone.
Still a half-completed, hulking concrete shell, the 71-storey building in China's southern industrial hub is billed to become one of the world's greenest office towers when it's finished late next year.
"We believe it will be the most energy-efficient tower in the world," said Roger Frechette, an engineer and the Chicago-based director of sustainable engineering with Skidmore Owings and Merrill LLP (SOM), the U.S. firm that designed the building and is overseeing its construction.
"Hopefully it will be the first of many built in the world. We really need them now," Mr. Frechette said in an interview during one of his many trips to Guangzhou. He calls the 2.2-million-square-foot tower "the project of a lifetime."
Though the total cost of the building has not been disclosed, it will use about $13-million (U.S.) in environmental technologies and adaptations, including wind turbines to supply its power, and heat-saving and cooling technologies to minimize the amount of electricity consumed. The tower's top 10 floors are to serve as the headquarters of the state-government-affiliated Guangdong Tobacco Co., with additional office space to be leased later.
The state affiliation has allowed the designers to test what they believe is a new frontier in sustainable construction, which they say at present may be possible only in China. While the recession has slowed building work in other booming centres such as Dubai (where SOM was the architect behind the spindle-like Burj Dubai skyscraper), massive government spending in China has kept the cranes operating.
Until recently, environmental concerns have taken a back seat to the incredible pace of development in China, where the government has resisted accepting targets to limit carbon emissions ahead of next month's UN climate summit in Copenhagen.
But there is increasing interest in the use of green technologies. Under law, China is required to produce 15 per cent of its energy from renewable sources by 2020. The 2006 law is driving the construction of massive wind farms, the world's biggest plant to convert sunlight to electricity, and an entire city - Ordos in Inner Mongolia - built on the concept of sustainable living.
In Beijing, developments such as the Modern MOMA office and residential complex include geothermal heating, wastewater recycling to feed its surrounding gardens, and a specialized indoor ventilation system.
But the Pearl River Tower is seen as one of China's most experimental buildings yet.
"When we first put the design together, we had a lot of people look at it, even in our own firm, who said, 'You're wasting your time. China's not really interested in sustainability,' " Mr. Frechette recalls.
"A lot of people made that assumption and I think it's wrong. ... In the last few years, we've seen China get very aggressive on sustainability."
Initially, the tower was designed to be a "zero-energy" structure, meaning it would produce as much power as it consumed using a series of wind turbines. Though that design had to be modified to fit local regulations, the tower will still use half as much power as regular office buildings for heating and cooling, ventilation and lighting.
Two floors of the tower will have wind turbines built inside; the building is designed to funnel the prevailing winds in through openings in its walls to keep the turbines running.
Double windows and automated window shades will help regulate the temperature; rooms will be cooled using chilled water run through copper pipes, saving space over traditional air conditioning systems.
The architects also promise that the cutting-edge ventilation system will produce better indoor air quality, a key issue in China where air pollution and outbreaks of airborne viruses such as H1N1 and, in years past, SARS are major concerns.
Opinions are mixed as to whether the tower will live up to its billing. "China's green technology must fit with China-specific conditions," cautioned Qin Youguo, a professor in the School of Architecture at Beijing's prestigious Tsinghua University.
"Being green here means the technology helps people in harmony with nature in a low-energy and sustainable way," Prof. Qin said. "What works as green technology in another country may not be green in China if it doesn't fit the situation here."
While Prof. Qin criticized many of the efforts thus far as showpieces with little real impact, others in the industry say real progress is being made. Architects say Chinese developers' interest in green concepts such as water recycling and energy efficiency is growing, and that clients are also calling for such ideas in project proposals.
"Generally, I can feel more interest of Chinese developers on the green concepts, such as environmentally friendly, power-saving, water-saving, low-carbon-emission [designs] especially in the last couple of years," said Ma Weijun, assistant chief engineer at Shanghai-based East China Architectural Design and Research Institute Co. (ECADI), one of China's leading architectural firms. "Sometimes, it is the clients' requests but we also guide our clients in this way. I can feel the change through our clients," Mr. Ma said.
Per cent of energy China is required to produce from renewable sources, by the year 2020.
Size, in square feet, of Pearl River Tower in Guangzhou.
Number of floors in the 71-storey skyscraper that will house large turbines, which will harness wind energy to help power the tower.
Value (U.S.) of green technologies being used in the building.