The Mixed Use Tower in downtown Manhattan is made out of an external lattice steel structure and a central core. Designed to be an iconic and sustainable building, the tower extends the public space above the Battery Tunnel via a large horizontal structure containing an auditorium, which morphs into the main tower. The building houses an auditorium, a large shopping mall, office spaces, a hotel, a youth hostel and high-end apartments. It has a large observation deck and a wind-power system on top. A combined cycle gas-fired power plant supplies electricity and heat. A special cooling system helps cut down on power consumption. The shading systems are designed to prevent overheating.