The Wall of Green

We hear of green roofs a lot but not so much green walls. This is probably because in theory it's great but in practice green walls take a lot of effort. However the latest large scale green wall has emerged on PNC Financial Services Group Inc's building in downtown Pittsburgh. 'The wall is made up of 602 two-foot square panels. Each panel contains 24 evergreen plants'. The panels were anchored into the buildings frame after some of the granite facade was removed.

Not only is this visually awesome but it obviously has environmental benefits. 'The vertical garden, similar to a green roof, will help to cool the 30-story building. Preliminary studies show the south-facing living wall will be 25 percent cooler behind the wall than ambient temperatures'. A man in the green wall industry states that 'green roof installations have increased at about 30 percent a year over five years'. However it will be a while until this idea is widely used because 'on average green walls cost about $100 to $125 a square foot'.

In the mean time we can admire the public art the walls inadvertently create, whilst wondering how the plants are watered in the summer and who prunes and takes out the dead ones...