Case studies: Bosco Verticale, Milan

Bosco Verticale in the spring. Image credit: COIMA

Milan’s Bosco Verticale (Vertical Forest) twin tower project designed by architect Stefano Boeri and Agronomist Laura Gatti was an experiment: Could a building successfully provide a home for trees, birds, insects and people alike? More than five years since the first residents moved in, in light of the multiple awards the project has received, including being named in 2019 one of the “50 Most Influential Tall Buildings of the Last 50 Years ,there is little doubt that the answer to this question is a resounding ‘yes’.

In a June 2020 interview, Boeri explained: “I personally believe that we have to change in terms of how we deal with the concept of nature. Nature is not something that lives outside, a kind of autonomous sphere from our lives… We have to experiment with a totally different proximity with [it]…We have to imagine a kind of double simultaneous movement: one is the movement of the citizens in the direction of the forest, because the forest needs our help…, and the second is the movement of trees in the direction of the city”. With the vertical forest, unlike garden cities, the objective is not to move people to the countryside, but rather to invite nature directly into city homes – maintaining densities that help limit urban sprawl.

Jeremy Hines and the Italian CEO of Hine, Manfredi Catella wanted to “transform one of the darkest and abandoned parts of the Milan centre” recalls Boeri. The 71-acre area targeted for regeneration under the brand name “Porta Nuova” was formerly occupied by industry. It sat between central Milan and the Isola neighbourhood, a working-class community. Hines’ ambition for the site was to deliver 20 high-rise towers clustered around was would become the tallest building in Italy – César Pelli’s Unicredit Tower. The contrast with central Milan’s stone-faced boulevards or the Isola community couldn’t have been greater.

To this challenge, Boeri answered “yes, with pleasure but please let me develop this idea of the vertical forest, a high-rise building with trees”. The concept was initially met with scepticism: How will trees survive 100 meters high? How will risks associated with high winds be mitigated? How can maintenance be sustainable? How can irrigation be reliable? “For most people unfamiliar with trees, this project seemed too risky, and basically, impossible to realise” recalls landscape architect and agronomist Laura Gatti.