A sloped site is one that has some portion of the ground surface located on an inclined plane. Commonly, the ground has to be steeper than 3 percent (3 feet vertical change in 100 horizontal feet) to be perceived as being sloped. At 5 percent, the ground does indeed have a distinct slope to it. Ground surfaces greater than 5 percent are perceived as being more sloped and become increasingly difficult to work with as their degree of slope increases. However steep, all sloped sites possess a number of special circumstances
that should be thought about in designing a single-family residential site. The steeper the site, the more pronounced these conditions are.