Roof surfaces of the building accounts for the 20–25% of the total
urban surfaces, hence they can successfully used to reduce the air
and surface temperature of urban area. Cool and green roof,
widely described in the next paragraph, are used to mitigate the UHI
and the impact was proved by several studies. These techniques
can also have significant benefits on the energy performance
of buildings, providing passive cooling to the built environment.
This topic is of special interest because of the rapid increase of the energy consumption and peak demand for cooling in Europe and
in the Mediterranean basin.