Building blocks

At triple the height of other nations’ pavilions, the China Pavilion in the center of the Shanghai Expo grounds is an unequivocal, towering reminder of the country’s passion for construction, and of the direction of its ambitions – namely building more while using less.

While the pavilion structure incorporates traditional design elements, it also employs cutting-edge sustainable technology to minimize its environmental footprint.

The building is composed of four crimson columns which support a massive 30-meter roof made of wooden brackets, cut to interlock perfectly without fasteners in an ancient imperial style called dougong. To this traditional structure, architect He Jingtang added sustainable touches. Rainwater is collected and purified on the roof-top for reuse in a misting system that reduces demand for air conditioning. Low-emission glass doors and windows deflect heat from the interior and convert it into electricity for lighting.

While the green technology and traditional architecture used in the pavilion are separated by centuries – millennia even – they share one attribute: the rarity of their use in China. Dougong brackets, though structurally proven for over 2,000 years, have long been replaced by cement and resin roofs that don’t need to be installed by skilled carpenter. As for low-emission glass and other, more recently developed technologies to reduce a building’s energy demand, most have yet to be implemented here.

However, for China the opportunity cost of ignoring efficiency in the rush to build is not negligible. The rapid increase in Chinese automobile sales has many planners justifiably worried, but the main culprit when it comes to wasting energy is buildings. In 2009, buildings accounted for 30% to 40% of the country’s total energy use, according to China’s National Resource Defense Council (NRDC).

Attitude problem

Without a serious change in attitude, there is no reason to expect this ratio to change for the better. The World Bank estimates that between now and 2015, approximately half of the world’s new building construction will take place in China. Kevin Mo, a senior sustainable building specialist at the NRDC, fears that there is little support for making these buildings more efficient, because Chinese developers – coddled by years of energy subsidies – still think efficiency is too expensive.

"In 2007, the World Business Council did a survey among Chinese real estate developers and it showed that they believed green buildings cost 28% more on average to build," Mo said. "But in fact, they cost only about 5% more on average, [and] you save over time on expenditures for energy, water and maintenance."

It is no secret that the Shanghai World Expo planners hope to change this attitude by making the Expo a platform for green technology, and green buildings in particular. Both foreign and domestic companies appear eager to seize the marketing opportunity.

For example, as visitors wander around the Expo site, the Israeli pavilion hopes they will notice its solar tower. Designed to look like a giant golden flower, the tower uses hybrid solar technology from Tel Aviv-based AORA solar to power its pavilion. According to marketing representative Matthew Krieger, the tower uses a 100-kilowatt microturbine that generates electricity twenty-four hours a day, running on a mixture of thermal heat, diesel and bio-fuel. 

"In dense urban populations like Hong Kong or Shanghai, [such towers] could be placed in the outskirts of the city. The technology is unique in that it can be scaled up or down based on need, and the towers take up little space," he said.

Not all the technology is so obvious, however. The Swedish pavilion will be covered in colorful sheets of Prelaq Energy from SSAB, a company specializing in high-grade steel. This steel can reduce the pavilion’s energy consumption by approximately 15% and dissipate solar radiation to maintain the internal temperature, explained Roy Johansson, project manager for Prelaq.

The Swedish pavilion will also use sustainable building blocks produced by Germany’s Xella International. The product, called YTONG, is a type of autoclaved aerated concrete (ACC) that is five times lighter than regular concrete and requires one-fifth the raw materials to produce. These pre-molded blocks will be used in several areas of the expo, including the Moroccan pavilion, the pavilion of the French region of Rh?ne-Alpes, the Expo Theme Pavilion and the World Expo Performance Center.

Jean-Maurice Hebrard, a representative of the Rh?ne-Alpes Pavilion, said that the energy blocks are also good at insulation – a YTONG structure with a thickness of 4-5 centimeters provides the same thermal insulation as 7-8 cm of concrete. Autoclaved aerated concrete is hailed by some as the "building material of the future" for its vermin-, fire- and earthquake-resistant properties.

How these products will be brought to market is a separate question, but in some cases they have already established a presence in China. YTONG, for example, has manufacturing plants in Zhejiang and Shanghai, even though it is unclear whether there is a market for them here. Beijing, in some cases, has positioned itself to inherit the IP rights to certain technologies exhibited. A marketing manager at Xian Dai architects surnamed Yue said that the government has already acquired the intellectual property rights to the "Sun Valley" technology that will provide natural light in the Expo Axis area.

Another question is to what extent the Expo will really help drive purchase orders for better building materials. Richard Ping of Shanghai-based IG Vision, the event director behind China Sustainable Building Summit 2009, is cautious but optimistic about the role of the Expo in driving demand.

"Industry players have their own considerations – they are talking about the likely cost of green technologies and whether or not people are willing to accept them," he said. "However, the World Expo will show a lot of practice in sustainable building, and if [business leaders] can see the effects of the technology, they may consider investing."