Hegau Tower / Singen, Germany/ 1999‑2009
Size: 183,000 sq ft / 17,000 sq m
Height: 18 floors
Status: Completed 2009
Recognition: Council on Tall Buildings – Finalist; AIA Chicago Chapter Award
In the small town of Singen, Germany, a shift from industrial production to a service-based economy called for the design of a building to serve as a statement for change. Responding to this shift, Jahn proposed a simple, refined form: a long rectangle, which changes in height to form the tower. Hegau Tower’s design is a direct result of close collaboration between architect and client — a clear modernist expression in the first decade of a new century.
Linearity is reinforced through projecting glass screens and stairs and balconies at the building’s short ends. These straight lines are more than aesthetic — they facilitate an optimized energy/comfort system, limiting the need for technical equipment by reducing solar loads. The building is oriented to minimize direct sun exposure, while motorized shades filter sunlight in high-exposure areas. Inside, basic conditioning is achieved using integrated heating and cooling in the concrete slabs, leveraging the thermal mass of the structure to enable a more comfortable office environment. Meanwhile, a continuous convector prevents unwanted draft resulting from falling cold air in the winter while heating fresh air for natural ventilation year-round.