Case Studies: Debis Tower

Renzo Piano Building Workshop

Buildings are static objects. While they are fixed in space, the sun is in constant motion throughout the day and year. Many daylighting strategies do not account for the sun's motion, but some address it brilliantly, allowing building occupants to control and tune their environment. Berlin's Debis Tower is an example of a building using operable elements to supplement the basic design decisions that support good daylighting.

The attitude that occupants should have a high degree of control over their environment with an operable, layered facade impacted building development and detailing. Codes and site also shaped form. For instance, German building regulations mandate that all office workers must be less than 25 feet from a window and natural light. This norm impacts building form, giving rise to the atrium. Debis's important site - Potsdamer Platz, the historic center of Berlin - meant that urbanistic concerns had to be addressed. It was critical to maintain the traditional street edge and take cues from the city fabric. Debis Tower is essentially a full city block, with a center atrium hollowed out of building mass to provide light and fresh air.

Maximizing building surface area is one response to designing for daylighting, with the corollary that sun control is also necessary. At Debis, glare and other light control issues are addressed within a building envelope featuring substantial user control. The tower's double envelope and the layered facade on the lower buildings also addresses thermal and ventilation issues, resolved in a sustainable manner with occupant control.

Debis, a Daimler-Chrysler subsidiary created to engage in real estate development and management, among other business services, views the project as a model or prototype for future real estate endeavors. The complex is a test for innovations in energy conservation and sustainable building design. As project managers and occupants, Debis is in the position to learn - with the complex becoming a teaching tool.