The trees growing on buildings...

by Annalisa Audino

That town planning, architecture, engineering are changing is a fact. Just as it is true that all plans are gradually trying to give greater attention to the environmental impact, undertake to safeguard the green areas of cities and try to raise awareness among citizens in respect of the nature that surrounds them. But sometimes the design and art have the upper hand. As it is happening in Milan, where some buildings are designed as covered by an expanse of green up to represent almost a wood: real ecological skyscraper designed by Stefano Boeri.

In these months several activities are ending: the wind tunnel tests of Polytechnic and the design of a system of anchoring the roots of the trees, as well as a constant monitoring of home control applications for the new wood vertical. The goal is the realization within an area of over 300,000 square meters of buildings certificated only with the North American system of LEED (leadership in energy and environmental design). Particularly waiting the challenge on the Island for 29,000 square meters: it is, in addition to the two structures intended for habitation by Boeri (105 and 75 meters), the buildings signed by internationally renowned architects William Mc Donough (offices for 6,300 square meters) and Lucien Lagrange (residential 4 storeys). And all in record time: by 2013 Hines, the company promotion project, thinks to complete all new neighborhood.

In particular, the two buildings of Stefano Boeri will become one of the landmark of Milan that changes and look towards Expo 2015: covered an expanse of green, the two towers provide 120 large trees, 544-sized, over 4 thousand small shrubs. The trees will be planted on the four facades of the buildings and will protect the structure from excessive radiation of the summer months while let pass it in winter. According to the designers they'll fight also noise pollution, grabbing soot release moisture and produce oxygen. And if do they break? Also this was calculated. Evergreen plants, and Feuillants (chosen for their ability to live in conditions and not to create allergies), will get to 6 feet tall and a safe anchorage system will be well publicized to the wall.

«We will verify the plants one by one – explained Laura Gatti, one of the paesaggiste agronome – the real critical moment will be in the first two years, then the roots will make sure the structure. Paramount will be maintenance: sensors will monitor the growth, the need of water, the status of the basins, the steady anchor. There will also be a centralized watering system with probes». Obviously the distribution of trees has been carefully studied: ecological and ornamental plays characters so that the whole Green is recognizable as a system architecture. But is this really the right way to create green spaces in cities? Woods vertical to free climbing? Milan has an important tradition in the field of urban planning and design of the city as intimate connection between architecture, society and social trends: the example given, therefore, should not be to a masterful construction that sand create, firmly on the ground, the right balance between buildings (with solar panels, lifts that work with renewable energy, etc) and green areas?