Enforcement codes have been adopted by many communities in the past two decades that prevent dense trees or shrubbery next to homes, reducing property damage from wildfire.  New California building codes put into place in January, bans wood siding and shingling in fire-prone areas.  Several existing communities have begun retrofitting their structures to be more fire resistant.  The causes of the wildfires are still under investigation, although it is suspected that they will be labeled as human carelessness.