More on the greenhouse effect, this time a welcome one. The 2008 Olympics Games will be China's chance to present its best face to the outside world.

It is also a showcase for many companies -- Chinese and western -- to present the latest technologies in a whole range of areas including environmentally-friendly building design.

For example, the 70,000-square-metre building that houses the national swimming centre, more informally known as the Watercube, would normally take a lot of heating.

But PTW Architects, the Sydney-based firm that designed the Watercube, has used a Teflon-like material called ETFE to clad the building in what looks like a giant-sized version of bubble-wrap.

The ETFE cladding acts as a very efficient greenhouse and means that 90% of the solar energy falling on the building is trapped inside, so keeping the building warm during Beijing's bitterly cold winters.

The swimming facility will house 17,000 spectators and should be completed by year's end. In the past, the cities that host the Olympics have often struggled to complete their ambitious building projects in time.

Beijing wants to be the exception to the rule. It plans to have all 37 competition venues and 76 training venues ready by the end of 2007 -- seven month ahead of the opening ceremony.

More in this story in Architectural Record.