As all San Francisco residents know, San Francisco homes are built close together. The close proximity of one home to the next increases the risk of fire as one home burning can quickly spread. In the aftermath of the 1993 Oakland hills fires which destroyed 3000+ housing units, the CA state legislature enacted housing laws to help prevent future devastating fire. One of those laws deals with roofing materials. Homes deemed as high fire hazard homes by the Department of Forestry and Fire Protection or local agencies are required to use fire retardant roofing materials (Class A or better) if they are re-roofing 50% or more of their roof. Class C or better roofing materials may be used in areas not deemed as being high fire hazard areas.