Click on images at left for larger color views. [Google Earth link] A major element in Stuttgart 21 -- a project to transform the German city's 19th-century railroad terminal into a modern, regional transit hub -- is obviously the Main Station, designed by Ingenhoven Architects. Like the rest of the plan that turns the existing tracks 90 degrees and buries them underground in order to create development opportunities on the old rail yards, the Main Station's design is an important urban project, extending beyond merely an architectural response to become a major piece of urban design. This project has received a good deal of press lately, stemming from its receipt of a Global Holcim Award for sustainable construction last year and assertions that the station will be zero-energy, or carbon neutral, a phrase getting bantered about a lot lately as reduction of fossil fuels becomes an important consideration. Amazingly, the architects won the competition for the station ten years ago, three years after the Stuttgart 21 plan was developed. Their foresight will extend all the way to 2013, the anticipated completion of the station. At the level of urban design, the station incorporates an extension of the Schlossgarten, considered the most important public green space in Stuttgart. Nearly thirty light shafts will protrude into the park space, providing natural light for the station platforms below and allowing visitors above to see into this subterranean space. Further, the new station will preserve the existing, 19th-century Bonatz edifice as an "interface between the old and the new city," according to the architects. These light shafts are the key to the project. In addition to bringing natural light below, the apertures function as natural ventilation for the platforms (the main zero-energy component), and as the main structural elements for the roof/ground plane. Their tear-drop forms are elegant both from above and below, making it appear that they are peeled from the surface of the (obviously constructed) ground. While other developments have been -- like the station -- slow moving, the completed station will surely become a draw not only for development but for people from all over Germany and Europe.   Main Station in Stuttgart, Germany by Ingenhoven Architects 2007.06.11     Click on images below for larger views.