"For private land creating a defensible space is on the books but is not being enforced." That depends on the area... I am a volunteer firefighter in Marin Co

"For private land creating a defensible space is on the books but is not being enforced." That depends on the area... I am a volunteer firefighter in Marin County (basically San Francisco) and we do defensible space consultations all summer and the paid firefighters of Marin County do indeed drive around all summer writing fix-it sheets for homeowners that are in the wildland-urban interface.