Green roofs project , Tokyo

Dense cities, such as Tokyo, 
suffer from the heat island effect, 
with ambient temperatures
considerably higher than the 
surrounding countryside. 
The Tokyo government passed 

regulations in 2002 to ‘green’ buildings with trees, plants 
and grass. 
The regulations require ‘20% of every new, large private
 building and 30%of all public buildings’ to be covered in 
greenery (McCurry, 2004). 
One such example is at Roppongi Hills, a new project 
by the Mori Corporation – which is also claimed to be 
Tokyo’s  example of  compact city development
Sustainability features
Green roofs, it is suggested, have numerous
 sustainability benefits. 
In addition to reducing the heat island effect, they 
help to conserve energy and fuel because of their
 insulation value, and ameliorate storm water run-off 
through absorption. 
They enhance biodiversity and wildlife, and provide
 additional greenspace in crowded urban areas
 (Anon, 2004). Roppongi Hills provides 1300 m2 
of roof garden space. 
However, such ‘sky gardens’ tend to be for private
 use, and the public benefit may be slight.