The "bamboo house," a rectangular storied building that is common in China, is actually an innovative model of the low-rent social housing project that the Madrid municipal government developed for its citizens. For more than a decade, Madrid has conducted a deliberate evolution of housing projects on its soil. Europe's largest social housing project now employs renewable energy, the latest environment-friendly materials, advanced ecological technology, and efficient construction operations, turning the Spanish capital into a dynamic trend-setter for residential construction.

The bamboo house of Madrid is duplicated on a one-to-one scale at the UBPA; the entire building is encrusted by a layer of bamboo that functions to adjust lighting and provide balanced temperatures, acoustic and visual insulation. It occupies a ground area of 600 square meters and totals a constructed floor space of 2,900 square meters, but even at this size, the strong sunlight of the Mediterranean can provide enough energy for the building, hence realizing zero emissions. Considering the climate differences between Madrid and Shanghai, certain changes have been made to the reproduction, such as an alternative electricity source to supplement the original single solar power supply.

An integral part of the Madrid case is the "Air Tree," a tree-styled exhibition hall constructed with recyclable materials. It is topped with several units of solar panels that generate enough power for the building's self-sustainability. The air conditioning system used in the "Air Tree" functions through networks of fine water jets working in conjunction with installations of various species of climbing plants, such as honeysuckle and ivy. This bio-system helps to remove CO2 and purify the air.

The humanistic, environmental, scientific and acclimatization aspects of the bamboo house and "Air Tree" have made them great successes at various international architecture exhibitions. At the Shanghai Expo, they will exemplify proven practices, the potential of the city to transform social housing, realize sustainable development and utilize renewable energy.

The UBPA itself is in fact an experiment in all potentialities. The greater part of it sits on the original site of the Nanshi Power Plant, a thermal operation built in 1897. The area used to be a major source of urban pollution, and has now been transformed into an explorer of the future city whose scientific advancements will make all that a distant memory. Its construction employs new materials and technologies, such as water-permeable bricks, recyclable bored metal plates, environment-friendly concrete, the river-source heat pump, photovoltaic power generation and active light guiding.

The 165-meter-tall meteorological tower is a conversion of the power plant's chimney built in 1985. It sounds like a dramatic overhaul, and conveys the message clearly: the development and management of the future city advances through experiment, real-life practice and general application. The course of all such progress requires conceptual breakthroughs, exchange and diffusion. This is the dream of the World Expo and the reality at UBPA.