Bosco Verticale - The first vertical forest in the world, born in Milan!

Milan doesn't only focus on the past! After countless visits to churches, castles and museums, I decided to change a bit and focus on a more contemporary context. Because this city is constantly moving, I wanted to show a bit of what they've been doing in relation to something that has already been debated in media and class rooms, sustainability.

In reality, I intend to talk about one project in particular. Identified as the "first vertical forest in the word", the Bosco Verticale is composed of two residencial buildings which are in construction in the Porta Nuova district, in Milan. These buildings form part of the Projeto Porta Nuova, which aims to rebuild an area of more than 290 thousand square metres (the Garibaldi, Varesine and Isola areas) through the construction of parks, public and private parking, green areas and big buildings. The solutions adopted by the project have already secured the LEED (Leadership of Energy and Environmental Design) certification. Some of these solutions are: use of renewable energy sources, photovoltaic panels, highly efficient insulation, recycled and non-pollutant construction materials and the collection of rain water for watering the gardens.

Model representing the intended region for the Porta Nuova Project.

You can find more details about the Porta Nuova Project here:

http://www.porta-nuova.com/it/home/

And the Bosco Verticale, what's so special about it?

It's main idea ismetropolitan reforestation without use of a large area of land. Stemming from this principal, two towers are in construction, which will include in their structure approximately 900 trees (3, 6 or 9 metres high), as well as thousands more plants and trees. The buildings are 110 and 78 metres high and will contain the equivalent of 10 thousand square metres of forest. In terms of urban density, the buildings will be equivalent to 50 thousand square metres of detached houses.

Illustrated image of the finished work.

The project was designed by the architect Stefano Boeri, from Boeri Studio, who aimed primarily to combine the growth of cities with the green of nature. This idea, which was initially considered foolish, allowed a structure to be created with the following characteristics:

• Reduction of energy consumption by approximately 30%;
• Creation of a microclimate inside the building;
• Filter for dust particles;
• Stimulus for increased humidity;
• Energy production;
• Carbon Dioxide Absorption and production of Oxygen;
• Protection against sun radiation;
• Greater acoustic comfort.

Scheme responsible for the water and vegetation system.

Scheme responsible for the planting of trees to create a better environment for the building.

Source of the schemes and of the pictures: http://www.stefanoboeriarchitetti.net/?p=207

The project and construction of the Bosco Verticale demanded lots of research and planning. Professionals from diverse domains were recruited to investigate all the relevant aspects of the structure and the necessary proceedings to make it possible.

For the structural engineer, this was a big challenge since, beyond designing the conventional project, it was also necessary to consider the effort needed to get the trees. They needed to combine structural safety with the most favourable positioning for plants to grow (normally it was the places that the engineers desired least that involved the most effort). Due to the wind, the trees generated a great load on the structure. Therefore, to guarantee the safety of the building, the plants were placed in wind tunnels (in the Politecnico di Milano and also in the Florida International University of Miami), with the aim to test their stability. For the bigger trees, mechanisms were used which attach the base to the building, promoting greater safety in case of storms.

Work in progress.

To guarantee the conservation of the building, the structure needed to go through a rigorous waterproofing process.

Another extremely important step was the choice of the type of plants. They were evaluated according to the properties of the wood, their size and their format, with the purpose of finding the species with the best conditions to adapt to the new habitat. After the choices were made the trees were kept, for two years, where they could be monitored and could grow safely and healthily.

Detail of the front.

One of the most critical stages of construction was transporting the trees to the top of the building, a process that required a lot of care, due to the fragile nature of the plant. After being put down, the base of the tree was filled with special soil which has all the necessary nutrients and conditions for its development. Moreover, a group of specialised gardeners will be responsible for their maintenance, three times a year.

The water used by the building will be filtered and reused to water the plats, which has to be done through an automised system. As well as this, the towers will contain wind-power and photovoltaic energy in order to increase it's level of energy efficiency.

The completion of the construction of these 110 apartments is predicted to be the end of 2013, and 60% of its apartments have already been sold. The options are quite varied, from 60 square metre compact and functional apartments, to 495 square metre duplexes. This innovation, as expected, is not within the price-range of the majority of people, considering that the cheapest is 7 thousand euros for each square metre (the average is 9 thousand per square metre).

Bosco Verticale and Torre Unicredit, both from the Porta Nuova Project.

Area next to the building.

"I believe that Bosco Verticale incorporates the idea of sustainability integrated with technology, but it also provides an aesthetic contribution, thanks to its front which changes throughout the seasons", says the architect Stefano Boeri.

A unique, sustainable benchmark in the world of construction, sustainability is a theme that runs through the whole project", Manfredi Catella, from Hines - building company which is working on developing the whole operation.

"The presence of trees isn't, by itself, a guarantee of sustainability. In the best case scenario, they can absorb the emissions and, therefore, act was protection against pollution, but this aspect has nothing to do with the conservation of energy", Dante Benini, Milanese architect, on an international level.

Opinions about the building are divided. Questions relating to cost vs benefits, difficulties and spendings on maintenance, and its real efficiency, will be answered throughout the coming years. Independently of this, we can consider this to be a big step in the direction of a more balanced future.

Figures about the work:

• Localisation: Milan, Italy;
• Year: 2007 (in progress);
• Company: Hines Italia;
• Area constructed: 40 thousand square metres;
• Budget: 65 million euros.

The work in progress.

Part of the construction site.

For more details on the building, you can also have a look at these videos:

http://www.youtube.com/watch?v=zy2hn8PizwI

http://www.youtube.com/watch?v=jElwdo9x2xw

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