Green walls are green roofs gone vertical. PNC Financial Services Group has unveiled its new, six-story tall green wall, complete with the corporate logo. The wall is located on the building’s headquarters at Fifth Avenue and Wood Street in Pittsburgh, Pennsylvania.  The wall encompasses 2,380 square feet made up of 602 2x2 square foot panels with 24 plants per panel. Each of the panels will offset the carbon footprint of one PNC employee...more.