In Sao Paulo the future is looking green for new buildings. There’s a really cool building that has every external wall covered in growth. Deco Journal has pictures of the building known as Harmoania 57 and an english description of what exactly is going on. For those that speak Spanish, here’s a Spanish article with even more pictures.
The eco system which allows the vegetation to grow on the walls of the building is heavily sustained by a watering structure running through the concrete walls. The plants grow in little cavities specially designed for this purpose. In time, all the concrete should be covered in vegetation.
Last time we looked at Sao Paolo, they banned billboards.