In an effort to become one of the greenest cities in America, Philadelphia Mayor Michael Nutter signed the “Cool Roof” bill into law last month. The bill moves buildings away from the traditional black roof-tops which absorb heat and requires cooler colors, such as white or highly reflective materials which help reflect the suns heat. It is hoped that in doing so, air conditioning demands can be reduced by up to 30%.
The law will be enforced on roofs with flat tops (mostly commercial uses) and will not be enforced on buildings with vegetative (or Green) roofs or buildings using roof-top solar panels.
PECO recently unveiled their headquarters green roof, which can be seen below: