Homes and buildings in northern states show a preference by builders and most people for black or dark roof covering, whether asphalt layers or shingles with the purpose of obtaining maximun heat retention during the cold or winter months. However, it has been found that the effect of the black roofs on the heating of buildings is nil or very little due to the laws of physical sciences - hot air will always rise - thus the heating effect is lost through the top of the structure.
When people move to the southern states , like Florida, you need the help of the roof covering to maintain the houses cooler. It is considered that an energy efficient roof can be an asset to reduce energy consumption, thus the combination of a white or light roof with good insulation in the air space above the ceiling (attic space) will provide energy conservation (up to 20% or 25%) and a cooling effect for the building or houses.