Stefano Boeri's "vertical forest"
nears completion in Milan


News: a pair of skyscrapers by Milan office Boeri Studio are nearing completion in the Italian city, featuring as many trees as could be planted in a hectare of forest.

Stefano Boeri's "vertical forest" nears completion in Milan

The studio led by Italian architect Stefano Boeri came up with the concept of Bosco Verticale, or Vertical Forest, as a way to combine high-density residential development with tree planting in city centres.

Stefano Boeri's "vertical forest" nears completion in Milan

The first project born from this concept is now nearing completion in the Isola area of Milan's fast-developing Porta Nuova district. Two towers, measuring 80 and 112 metres, are set to open later this year and are already home to 900 trees.

Stefano Boeri's "vertical forest" nears completion in Milan

"The project is set to create a new standard for sustainable housing," said engineering firm Arup, who is working alongside Boeri Studio to deliver the project.

"As a new growth model for the regeneration of the urban environment, the design creates a biological habitat in a total area of 40,000 square metres."

Stefano Boeri's "vertical forest" nears completion in Milan

A mixture of large and small trees have been planted on balconies on all four sides of the towers, accompanied by 5,000 shrubs and 11,000 floral plants. The design team claim these will absorb dust in the air, helping to depollute the city.

"This is a kind of biological architecture that refuses to adopt a strictly technological and mechanical approach to environmental sustainability," said Boeri Studio in a statement.

Stefano Boeri's "vertical forest" nears completion in Milan

The diverse vegetation will provide urban habitats for birds and insects, and will also create a humid micro-climate that produces oxygen whilst shading residences from harsh sunlight.

"The creation of a number of vertical forests in the city will be able to create a network of environmental corridors which will give life to the main parks in the city, bringing the green space of avenues and gardens and connecting various spaces of spontaneous vegetation growth," said the studio.

Stefano Boeri's "vertical forest" nears completion in Milan

Photography is by Daniele Zacchi.

Here's a project description from Boeri Studio:

Bosco Verticale/Vertical Forest

The Vertical Forest project aims to build high-density tower blocks with trees within the city. The first example of a Vertical Forest is currently under construction in Milan in Porta Nuova Isola area, part of a larger redevelopment project developed by Hines Italia with two towers which are 80 metres and 112 metres tall respectively, and which will be able to hold 480 big and medium size trees, 250 small size trees, 11.000 groundcover plants and 5.000 shrubs (the equivalent of a hectare of forest).

The Vertical Forest has at its heart a concept of architecture which demineralises urban areas and uses the changing shape and form of leaves for its facades, and thus which hands over to vegetation itself the task of absorbing the dust in the air, and of creating an adequate micro-climate in order to filter out the sunlight. This is a kind of biological architecture which refuses to adopt a strictly technological and mechanical approach to environmental sustainability.

Stefano Boeri's "vertical forest" nears completion in Milan
Proposal rendering

Biological habitats

Vertical Forest increases biodiversity. It helps to set up an urban ecosystem where different kinds of vegetation create a vertical environment which can also be colonised by birds and insects, and thus becomes both a magnet for and a symbol of the spontaneous recolonisation of the city by vegetation and by animal life. The creation of a number of vertical forests in the city will be able to create a network of environmental corridors which will give life to the main parks in the city, bringing the green space of avenues and gardens and connecting various spaces of spontaneous vegetation growth.


Vertical Forest helps to build a micro-climate and to filter dust particles which are present in the urban environment. The diversity of the plants helps to create humidity, and absorb CO2 and dust, produces oxygen, protects people and houses from the suns rays and from acoustic pollution.

Proposal rendering


Vertical Forest is an anti-sprawl measure which aims to control and reduce urban expansion. If we think of them in terms of urban densification, each tower of the Vertical Forest is equivalent to an area of urban sprawl of family houses and buildings of up to 50,000 square metres.


Trees are a key element in understanding architectural projects and garden systems. In this case the choice of the types of trees was made to fit with their positioning on the facades and in terms of their height, and took two years to conclude alongside a group of botanists. The plants used in this project will be grown specifically for this purpose and will be pre-cultivated. Over this period these plants slowly got used to the conditions they will be placed in on the building.creating an adequate micro-climate in order to filter out the sunlight

Vertical Forest is a landmark in the city which is able to release new kinds of variable landscapes which can change their form in each season depending on the types of plants involved. The vertical forests will offer a changing view of the metropolitan city below.

Section - click for larger image


The management of the trees' pots is under building regulation, as well as the upkeep of the greenery and the number of plants for each pot.


In order to understand the need for water the plan for these buildings took into account the distribution of plants across various floors and their positioning.

Architecture: Boeri Studio (Stefano Boeri, Gianandrea Barreca, Giovanni La Varra)
Landscape: Bosco Verticale Landscape Design (Emanuela Borio and Laura Gatti)
Developer: Hines Italia

Concept sections - click for larger image

Supervision of works: Francesco de Felice, Davor Popovic
Design development: Gianni Bertoldi (coordinator), Alessandro Agosti, Andrea Casetto,
Matteo Colognese, Angela Parrozzani, Stefano Onnis
Schematic design and PII: Frederic de Smet (coordinator), Daniele Barillari, Marco Brega,
Julien Boitard, Matilde Cassani, Andrea Casetto, Francesca Cesa Bianchi, Inge Lengwenus,
Corrado Longa, Eleanna Kotsikou, Matteo Marzi, Emanuela Messina, Andrea Sellanes

Structures: Arup Italia s.r.l.
Facilities design: Deerns Italia S.p.A.
Detailed design: Tekne s.p.a.
Open Space Design: Land s.r.l.
Infrastructure design: Alpina S.p.A.
Contract administration (DL): MI.PR.AV. s.r.l.

  • treehugger

    Those poor trees, just having decorative character so this designer can call his project a green building. The last section is really pathetic, 0,5m³ for a tree. Can this be enough? Or is it just a bush?

    Why didn’t he just paint the building green? This wouldn’t stress the trees that much.

    • racosin

      Actually the section showing the planter on the balcony is more than sufficient to hold a tree of the size shown. The problems they would have is to pin the rootball down and also to make sure it receives adequate amount of water for its growth, which can easily turn into a services nightmare if not done properly.

      The trees would grow fine and not be stressed if they are taken care of… just like any other garden. Knowing about nature is different from taking care of a garden.

    • Ano_Nym

      I would guess they’ve done some research before they gave a green light to a multimillion project like this.

  • treehugger

    i doubt this “designer” knows anything about nature!

    • Airborne

      Didn’t know this site attracts tree-huggers.

      I have seen trees in large pots before. They are a great enhancement to any site or building where there is not enough soil. Great project.

  • So, Milan is the Italian capital now? Seriously? Check your facts before you publish. You may have heard that it is rule #1 of journalism.

  • Wigspotter

    This is wonderful. Say what you will about green credentials; I’d prefer a city full of trees than Dubai glass boxes any day of the week.

  • :(

    If they did some research they would know that the roots of the trees are kind of proportional to his crown. And those trees pots don’t look big enough; poor trees :(

  • Pipo

    I’m a firm believer that the earth is changing and we, humans, play a minuscule factor in that change. As humans (self narcissists) we think we must have an explanation for everything we don’t understand just to make us feel ‘up to par’ with the nearly perfect natural world that we have absolutely no clue about.

    Therefore I believe building these kinds of “green” “responsible” buildings seem rather silly and are nothing more than knee-jerk reactions to an imaginary problem designed to artificially make us feel better about ourselves.

    This project is pretty and nothing else.

    • NotAnEcoWarriorButStillAware

      Unfortunately it appears you lack any rationale or even the slightest fragment of intelligence.
      Humans probably play the biggest role in how and why the Earth is changing. i.e. climate change, green house gases, destruction of ecosystems, general destruction of nature and habitats. These are not “imaginary problems”.
      We have a responsibility to build with low energy and low carbon emissions in mind to attempt to reduce the human impact on the earth.
      Architects and designers are increasingly occupying themselves with ‘green design’. Whether this is merely gestural or self-serving is another debate.
      Also as humans have learnt a fair amount about the “near perfect natrual world” which is precisely why we understand our impact on it.

      • Pipo

        If course, the typical personal ignorant rant/attack. Keep drinking the kool aid bud.

        • Annette Parker

          Let me guess, are you an American who drives to the mall 2 metres away?

      • Grant

        You might want to look at the other side if the argument. Pipo has a good point. The climate does and will always change. Earth was a giant ice ball billions of years ago and has gotten a lot warmer since. It’s also gone through through cooling cycles, it’s natural fluctuations not human interference. Solar flares and ‘changes’ in the moons rotation affect the oceans thus provoking changes on earth. Besides, other planets have climate change and changes in temperature as well without human causes. Wonder how Billonaire Al Gore would explain that? I’m sure he’ll blame us on earth for causing changes on Mars. No matter what, people such as yourself will never want to look at the facts and the immense complexity of what is causing the earth to change because it doesn’t fit the narrative of blaming humans.

      • Annette Parker


        No point of teaching these idiots. They will do anything to remain ignorant and shirk responsibility.

  • Amit

    What kind of trees can survive with such shallow roots? More curiosity then criticism.

    • eman

      Pioneer trees start to grow on abandoned buildings by themselves even though there is nearly no soil at all. Also, there are trees that grow on exposed cliffs or high mountain regions. This building should provide kind of the same conditions. These trees just grow slower and have smaller leaves when they have only little soil. Bonsais are an extreme example.

  • Yogi

    This is amazing.

  • yogi

    This is excellent. The idea of a vertical forest is conceptually cliche, but I don’t think i’ve ever seen one realised! Very exciting. I have my doubts as to how well it’ll work in the long term, and part of me wants it to fail and the trees to take over the building. I hope it attracts loads of wildlife. Awesome. Great job. Pushing the boundaries.

  • don

    Uh – wind?

    • w.n.p.

      Let me add: uh – winter?

  • collina

    The idea is ok. I wonder, when there is strong wind, if the trees will fly away… maybe onto the street.

  • Airborne

    The current situation cannot be compared with natural changes that took millions of years. It cannot be denied in what appears to be a fraction of a second on the evolutionary clock, a biological entity is consuming all natural resources and discharging megatons of CO2 in the atmosphere. Species cannot undergo evolutionary adaptations in such a short time span. Any activity that either creates awareness or contributes to a solution, no matter how futile, should not be ridiculed. It can trigger new ideas.

    If nothing changes we are heading for large scale conflicts where nations fight over the last available resources. What China is doing at the moment by invading the territorial waters of Vietnam to drill for oil is a dangerous precursor.

  • JC

    Must be pretty dark inside the apartments with all the shrubbery.

  • Aurelijus

    Dope. Looks dope. I don’t care if it’s not good for trees. I’m a fan of dopeness.

  • DHD

    Green building is not about vegetation!

  • orangeeli

    If a tree falls from a 100 meter forest when everyone is around, do the pedestrians make a sound as they are crushed?

  • Ben

    Bonsai work; why shouldn’t these?

  • Marty

    Written: “The diverse vegetation will provide urban habitats for birds and insects, and will also create a humid micro-climate that produces oxygen whilst shading residences from harsh sunlight.”
    Read: “Be ready for all of the bugs and bird poo all over your balcony. Oh yeah, and don’t expect any natural light to come in through those nice big windows. You can’t remove leaves like you can open blinds you know. PS. It’s gonna be humid as hell in the summer… Enjoy!”

  • Erik Van Lennep

    I have been following (not avidly, but aware of) this project for a couple of years now. I am glad to see it has come this far, because we need to test such audacious concepts to work out the details.

    But from the comments posted by a number of others, it should also be clear that “concept” is an issue in the execution of design. In more than one way, this design follows the classic concept-led approach.

    This shows up by some of the critiques posted: lack of air and sun into the apartments (Milan is muggy enough as it is in the summer, and foggy and drizzly in the winter, so both air circulation and light are important).

    It’s easy enough to make a building or a garden (and this is both) look brilliant on opening day, but come back in 12 months, or 3 years, and that is when the resiliency of the design shows itself. In this case, will bonsai trees stand the test of time?

    That depends on the follow through from building management. To the comments which mentioned bonsai in planters, in true bonsai and most planters, the trees need their soil physically renewed on a semi-annual basis, as well as the larger roots pruned away to stimulate fresh “feeder” root formation. I doubt that’s in the maintenance schedule.

    It would be interesting to know if Arup did the obvious in terms of “green design” and include grey water filtration systems which deliver irrigation from apartment waste water to the planters.

    It would also be informative to see a list of the species being utilised. I am sure there will be a learning curve for everyone involved.

    I am curious why a mega-consultancy the size of Arup is still stuck in the last century, when both sustainability and 21st century design require architecture to be far more responsive, and far less concept-driven (i.e. imposed). The list of concerns and comments resulting from this article are just a sample of questions which responsive design should address before plans are signed-off.

  • moi