The largest living wall in North America was recently completed at One PNC Plaza in Pittsburgh, the headquarters of PNC Bank. The 2,380 square-foot living wall has 602 2′x2′ modular panels, each one containing 24 plants for a grand total of 14,448 plants. The greenery, complete with PNC logo, covers a vast section of the exterior wall of this 30-story building. Since its installation, studies have shown that the south-facing wall is 25% cooler behind the green wall than ambient temperatures.
The world’s largest green wall was constructed for Japan’s Aichi Expo in 2005, a massive ‘bio-lung’ measuring 150 meters long and 12 meters high. The wall consisted of hemp canvas called ‘kenaf’, with pockets planted with sedum, vines and flowers. It was named ‘bio-lung’ to convey the message that such expanses of vertical vegetation can function as a huge, breathing lung to purify the air in urban environments.