THERE'S a risk of becoming complacent in Shanghai about man-made modern structures, such as multi-tiered overhead freeways, huge transit centers, underground networks, buildings and neighborhoods that seem to disappear overnight and others that materialize almost out of nowhere.

There seems to be no end to construction inventiveness, quite apart from the extraordinary Expo developments, and just when you thought nothing else could be done to surpass the city's design creativity, an even more astounding project will emerge.

Marshall Strabala, 48, is the designer of China's soon-to-be tallest building, the 632-meter Shanghai Tower, and he's deeply into the business of ultra high-rise constructions, having designed the Burj Khalifa in Dubai, the world's tallest building at 828 meters.

As we sat last Monday morning in the foyer of the Portman Ritz-Carlton, a 60-hour concrete pour to form the base of the Shanghai Tower's foundations was in its final stages after more than 400 trucks delivered 61,000 cubic meters of concrete to support the 800,000-ton skyscraper.

Strabala has been living almost full-time in Shanghai for the past two years as he's nurtured the approved 121-story tower design through a comprehensive peer review process up to the point now where his schematics become the development blueprint for builders to move in.

Shanghai Tower will be the big brother of three in the Lujiazui neighborhood, dwarfing the current tallest building on Chinese mainland, the 492-meter Shanghai World Financial Center, and towering over the 420-meter Jin Mao Tower when it opens in 2014.

US-born Strabala clusters the three buildings into a time context as he compares construction on the Pudong New Area side of Huangpu River with the Bund.

"The Jin Mao is a building of China's past and represents a stainless steel pagoda, a modern interpretation of a Chinese building, and I think it's very well-loved because of that," he said.

"We think of the WFC as a representation of China's present which accepts foreign investment, an opening up of China, a very sleek, modern building that doesn't refer to China's past. Our building is designed as the third of three brothers and represents China's future."

As the river becomes a stronger delineator of old and new Shanghai and brings into sharper relief China's past and its modern, rapid development, the buildings on Pudong side contrast rather than compliment the architectural icons on the other bank.

"The buildings along the Bund are absolutely gorgeous and they were built from the early 1900s in a style of architecture using the construction technology of their time," Strabala noted.

Most advanced

"They were probably the most advanced in Shanghai when built. But today we don't build in tribulation, in posts and beams, we build in mega frames and outrigger trusses using composite concrete and steel.

"Architecture should be built of its time with the knowledge we have today, just as doctors don't use leeches to bleed people, they use anesthetics and new ways of improving the art form. It's the same with architecture."

Strabala has always had an interest in high-rise buildings and with the world's tallest in Dubai and the Shanghai Tower, he is also designer of the new 450-meter Nanjing Greenland Financial Center, structures which give him three of the world's top 10 tallest.

Among 50 or so buildings he's designed in Europe, Asia and North America, the Seattle-born, Harvard-educated architect was also responsible for Phase 2 of the Hong Kong Convention and Exhibition Center.

"It's become common for me to do super high-rise buildings and there are only a few architects in the world known for them: Caesar Pelli has three and Adrian Smith has three," he said.

"With these buildings, it's like a heart operation. You wouldn't go to someone who hasn't done one before, even though they understand the theory. You want someone who's done a thousand of them. There's about 10 people in the world like me doing them and we're called the usual suspects."

Strabala becomes enthusiastic over design details of the Shanghai Tower which are complex minutiae to mere mortals but are intrinsic to his building and hallmarks of its appearance and functionality.

In introducing the building's "double-skin" construction concept, he likens it to a thermos bottle, explaining the insulation layer created between the conventional, glass-fronted building inside and a second glass layer twisting around it.

"If you can insulate your building and stop the heat and cold from migrating, that's the most bang for your buck," he said.

"The internal structure is a series of 14-story cylinders stacked up on top of each other. They represent nine different zones, with amenity floors every 12-15 floors.

"Then the outer skin wraps over it and twists as it goes up to create the shape of the building. We chose a shape that is very tight around itself so you get 60-70-meter atriums for restaurants, conference facilities and other amenities," he added.

"The twisting of the building and how the sun hits its soft corners is what you'll see on the skyline but everything about it is designed to mitigate the wind forces."

Strabala said he had to balance the "iconography" of the building with its functional performance and found in trials that twisting the outer skin to 180 degrees further reduced wind forces. However he agreed to 120 degrees of twist "because the client didn't want a bent building."

His design was chosen from nine others and he believes there is more vision alive in China for such projects than in America where cost restrictions cause buildings to "get whittled down to almost nothing."

"These ultra-tall buildings become a signifier of a city. Low buildings like the Sydney Opera House are equated with cities but tall buildings are the ones that show up on postcards and say 'this is Shanghai' or wherever," he said.

He believes that while the Shanghai Tower will be the world's second tallest building when completed, others may overtake it in time. He does not subscribe to height competitions and believes trying to be the "tallest building in the world is kinda dumb, there has to be some other reason to do it."

"If half the world's population is going to live in urban centers by 2050, we can't keep building outward on five to six stories until all the cities merge, you have to build up and over subway lines," he said. "You're creating almost a virtual city and need the infrastructure to deliver 20,000-30,000 people a day."

With the design phase over, Strabala has finished as director of design with Gensler global architecture firm and will have reducing involvement through the next stages.

And as he contemplates new projects, with three possible in China, he cites the sentiments of the tower's construction consortium chairman, Kong Qingkei.

"He said 'this is my gift to the people of Shanghai,' which was a very romantic thing to say. He wanted it to be the best building in Shanghai."

Designer's key points about the Shanghai Tower

Designed for 28,000-30,000 people a day based on building code requirements, but actual usage will be about 21,000 daily in and out of shops, hotel and offices.

With 121 floors, there will be two hotel zones at the top, five office zones, then retail, conference, restaurants, sunken plaza and a link at B2 to the subway.

With 8 percent of people lunching on amenities floors rather than travelling 80 floors to ground level, it will save 850,000 elevator trips a year and equate to an annual US$10 million saving in electricity.

At every 15th floor, there will be a 14-floor atrium. The 27 atriums will be "plazas in the sky" affording views of the entire city on more viewing platforms than any other building in Shanghai.

At an expected cost of 15 billion yuan (US$2.2 billion), it will be the world's tallest "double-skin" building.

On glass mounted on a stone wall at the building's entry will be etched every family name in China.