Amid the dynamic worldwide efforts to protect ecological environment, green architecture is becoming the main trend in the development of modern architecture.
Applying the principle of ecology, green architecture minimizes the consumption of natural resources and energy and provides people with the most livable environment.
Populous cities are pushing the creation of “hanging gardens” and “hanging greens” while focusing on roof greening in particular.
Roof greening is classified into flat and cubic types according to greening space, ecological and relaxation types according to purpose and peripheral, fixed and mobile styles according to form.
Many countries show great interest in greening roofs of urban buildings.
“Hanging gardens” are being built on the roofs of public buildings in Buenos Aires, Argentina.
They not only enhance heat insulation efficiency on the roofs of high-rise buildings but increase the oxygen content in the air and absorb carbon dioxide. They also filter dust out of the air to keep urban environment clean.
In order to encourage roof greening, the city government has taken a measure to deduct tax up to 20 percent at the maximum according to the greening rate of roofs.
Another country built the world’s largest greenhouse on the roof.
Covering an area of 15 000 square metres, it produces such vegetables as eggplant, tomato, lettuce, cucumber and celery and nearly 100 kinds of aromatic plants every year through hydroponic culture.
Roof greenhouses in general make the effective use of electrical, heating and water supply and drainage systems of the buildings under them and the waste gas and heat from them as well. The waste gas from them contains more carbon dioxide necessary for the growth of plants than the air.
A European country which started roof greening for the first time in the world has realized roof greening on 12 percent of buildings and created “hanging greens” in an area of 15 million square metres in 2013.
And another country is working to create 300 000 square metres of such area every year.
Different countries have set roof greening as one of important policies for improving environment and positively introduced a smart control system to that end, while researching to apply a computer-based integrated monitoring system to creating optimal humid conditions for roof greening.