As stated earlier, current building practices result in large amounts of any building lot being covered with impervious surfaces such as asphalt, concrete and the house or commercial building itself with its metal, shingle, or membrane roof.

According to Environmental Health Perspectives, reprinted on-line by the National Institute of Health, as much as 10 percent of a two acre home site and 65 percent of a 1/8 acre lot will probably be covered with some sort of 'paved' surface.

Publish Date: 02/13/2006