The building is being wrapped in corragated galvanized metal- somewhat for aesthetic reasons, but mainly for durability. The steel is ‘hot dipped’ in zinc which causes the galvanization process- by which the inside is steel, the outside is zinc and the middle product becomes a mix of zinc and iron- binding to the metal in a way that is more than just paint. If you want to know more you can click here.
Elementalbuilding 