The 110,000 m3 excavation pit will be a Net-Zero construction site. The consortium Baugrube HPQ Mitte and Nord with the executing companies Keller Grundbau and Kern undertakes to reduce the CO2 emissions caused by excavation and shoring to a maximum and to compensate the remaining emissions accordingly. This alone will already save approx. 4,400 t of CO2 - this corresponds to the emission value of approx. 1,100 return flights between Hamburg and New York. All in all, the CO2 equivalent of approx. 8,200 t originally calculated for the construction pit will be reduced to approx. 3,800 t. The CO2 emissions from the construction pit will also be reduced. These are then offset in cooperation with certified companies through appropriate projects, such as forest reforestation. The entire process and the balancing are carried out in close coordination with the consulting companies agradblue and SBC.