The Heinrich Böll Foundation is closely linked to the political party Bündnis 90/Die Grünen and is committed to promoting democratic decision-making, socio-political engagement, and international understanding around the globe. The Foundation headquarters are centrally located on an undeveloped site in the district of Berlin-Mitte. The building is in a park, surrounded by trees, but it is located at the edge of the park and has a small footprint. The design concept is both radical and pragmatic: based on a limited budget, it clearly prioritizes how much money should be spent in which areas. The main efforts and resources concentrate on the office levels, expressed as an overhang clad with green glass panels, generating a covered outdoor space at ground level and giving the complex a civic character. Moreover, on a functional level it houses the conference halls that permit different combinations and layouts. Meanwhile, the rest of the offices are organized soberly and efficiently, and the structure is exposed. And in terms of energy efficiency, the building uses only 40 kWh/m2 per year, which is less than half of the legal maximum. This makes the building a leader in the field of sustainable modern office and conference center design...[+]