For a long time this TreeHugger was skeptical of hugging Stefano Boeri's Vertical Forest concept, but others thought it the most beautiful and important high-rise in the world. Now Boeri is building his third complex, the Nanjing Vertical Forest. It will have 1100 trees from 23 local species, covering 60,000 square feet of plantable area. The architect says it will provide a 25 tonnes of CO2 absorption each year and will produce about 60 kg of oxygen per day.

My initial skepticism focused on whether the planters were actually big enough to support the growth of such big trees, and whether making the extra concrete needed to build them produced more CO2 than the trees would ever absorb. But Boeri made a convincing case that his buildings were an "anti-sprawl device".

[Vertical Forest 1] constitutes an alternative urban environment that allows to live close to trees, shrubs and plants within the city; such a condition can be generally found only in the suburban houses with gardens, which are a development model that consume agricultural soil and which is being now recognized as energy-consuming, expensive and far from communal services found in the compact city.

© Stefano Boeri

Given the amount of concrete it takes to build sprawl-based development, this was a plausible justification for the extra concrete in the building. However, the Nanjing buildings serve a different function.

The taller tower, 200 metres high, [656'] crowned on the top by a green lantern, will host offices - from the 8th floor to the 35th – and it will include a museum, a green architecture school and a private club on the rooftop. The second tower, 108 metres high [354'], will provide a Hyatt hotel with 247 rooms of different sizes (from 35 sqm to 150 sqm) and a swimming pool on the rooftop. The 20 metre [66'] high podium, will host commercial, recreational and educative functions, including multi-brands shops, a food market, restaurants, conference hall and exhibition spaces.

© Stefano Boeri

The question of whether the buildings will ever look like the renderings remains a source of skepticism. The most recent photos that I can find of the original Vertical Forest in Milan do not look encouraging, although this photo was taken in November 2016 and it certainly is going to take a couple of years for everything to settle down and find its roots, so to speak.

Google Earth/via