Green roofs are a growing trend in the U.S. But PNC Financial Services Group is taking the lead on green walls, with the largest Green Living Wall in North America scheduled to be constructed on the south side of the bank's Pittsburgh headquarters. When completed the 2,380-square-foot wall, outfitted with 602 panels of soil, will look much like a painting constructed out of regional plants. The wall will also provide shade to surrounding sidewalks, absorb sound, and cool the surface of the south wall by 70 to 80 degrees...more.