The European Investment Bank building in Luxembourg uses natural climatic control zones and large winter gardens to regulate temperature, acting as the building's "lungs". Pipes circulating chilled water through concrete slabs use thermal activation to cool the structure without energy-intensive cooling systems. Ventilation moves air from lower winter garden areas to upper vents. The building's energy concept focuses on the winter gardens and atrium as thermal buffers, thermal activation of the building structure, and powerful natural ventilation to control temperature and minimize energy consumption.