~ A novel take on a green-walled building is under construction in Milan.
The Bosco Verticale (Vertical Forest) places trees on custom-designed ledges all the way up the outside walls of the two apartment towers.
Each apartment balcony will have trees (900 plantings are planned for the two buildings) that will provide shade in the summer and drop their leaves in winter to allow in winter sunlight. Plant irrigation is provided via a grey-water filtration. Additionally, photovoltaic power generation will help provide sustainable power to the building.The comment thread to the article is divided between those who think the idea is wonderful and those who find it an abomination against nature. Both sides question its practicality, and there are indeed many concerns with how well it can work, and work over time, including the mass and effect of the tree roots, the weight and efficiency of watering, the challenge of pruning, falling detritus, depletion off the soil, the long-term health of the trees, etc. It is a very large initial trial of a bold vision. Others are contemplating vertical forests as well, so new and perhaps better designs may be possible.
The designing architect's web site shows the first tree being lifted into place, and other trees are said to have been added since April 2012. It is claimed that the building will be ready for occupancy this year, but I can find no pictures the show the progress one might have expected in planting all those trees as envisioned. Perhaps, since the trees are deciduous we must wait for spring or summer to see it fully feathered.