With a name like TreeHugger, we pay a lot of attention to the work of Stefano Boeri, starting with his Vertical Forest in Milan and more recently with his proposal for the Nanjing Vertical Forest. In fact, the Italian architect now has an office in Shanghai and is planning entire cities covered in forests.
Forest City Shijiazhuang will house 100,000 people in what Boeri calls an "anti-sprawl device" because it is so dense, housing the same number of people in 225 hectares, or 555 acres, what is normally in 25,000 hectares. (That's 44,000 people per square kilometer, which is seriously dense. However they are small pockets of high density, surrounded by farmland. Boeri tells the Guardian:
“What they have done until now is simply to continue to add new peripheral environments to their cities. They have created these nightmares – immense metropolitan environments. They have to imagine a new model of city that is not about extending and expanding but a system of small, green cities.”
Boeri's website shows the concept for Shijiazhuang, a large polluted city a hundred miles southwest of Beijing. He calls it "is the prototype of a new model of urbanisation in China, which doesn’t consume agricultural and natural lands, limits the costs of public transportations and reduces the energy consumption. " He claims that the ForestCityShijiazhuang (FCS) will be:
- a sustainable city, with low energy consumption The vegetative filter on the buildings balconies creates a reduction -in the difference between the outside and inside temperature- of about 3 degrees. In summertime it reduces the heating of the facades by up to 30 degrees.
- an absorber of CO2 and the dust of urban pollution: FCS cleans the air The vegetation within FCS is designed in such a way as to form a continuous green filter between inside and outside of inhabited areas, able to absorb the fine particles produced by urban traffic, to produce oxygen, to absorb CO2, and to shield the balconies and interiors from very high pollution of Chinese cities.
- a multiplier the biodiversity of the living species FCS will be the home of hundreds of different species of plant life, including trees, shrubs and perennials. FCS will host many species of birds and domestic animals.
Boeri envisages a chain or line of these, all based on the math of 225 hectares of dense development inside 25,000 hectares of green space, used for agriculture, nature or sport. (or is it 2,500? both numbers are used on the same page, and it makes a big difference)
It is a planning concept that we have seen proposed for China by Broad Sustainable Buildings, where they wanted to build a city in a single building and surround it by parkland, or in the Vertical City proposal. What Boeri is proposing is really a tree-covered Arcology.
I have expressed reservations about Boeri's work and the jury is still out about whether you can actually cover buildings with trees like this. However the planning principle makes a great deal of sense.