Increasingly cities cover of vegetation the roofs of buildings to improve the urban environment and to reduce the CO2 emissions and the energetic expense.
The idea of draping with a vegetable cover the top part of the buildings was already used by people like the vikingos and other ancient civilizations. Some of them compare them with the hanging gardens of Babylonia as precedent of these facilities.
3D representation of the hanging gardens of Babylonia
Apparently, the impellers of these modern systems are placed in the decade of the 1960s in several Scandinavian countries and of Central Europe, fundamentally Germany.
Some estimations show that in this country 20 % of the flat roofs are covered with these systems. Other European countries like Great Britain or Holland also have important developments.
Hotel in the Italian Alps
In The United States of America, the cities of Portland and San Francisco are considered like the first ones in installing these ecological roofs in the 80s.
Manhattan, New York, USA
Some years later, associations and specialized companies of other big cities, as Chicago, New York or Washington have been stimulating this construction. Also, in Latin America countries, as Mexico, Argentina, Uruguay, Chile and Brazil, this system is promoted.
Hospital Sao Vicente de Paulo, Rio de Janeiro, Brasil
The green roofs are not only agreeable at sight but they improve the air and have considerable technical - constructive advantages and also physical - constructive; they are cool in summer, warm in winter and prolong the useful life of the roof.
Green roof system
This system reduces found water runoff by over 75% during rainstorms.
The gardens and green roofs absorb CO2 and other harmful substances produced by the urban activities, purify the air and produce oxygen. In addition it helps to reduce the noise.
These gardens can be made in roofs, balconies, terraces, building foreheads and even in walls inside closed spaces; but, they have to be designed by experts in order that they choose the kind of plants more adapted for every place.