California has more wild fires, in large part, because its expanding population is wealthier and has migrated into outlying areas in historically fire prone wild land areas. As homes move in, so to do more power lines which are subject to start fires when wind blown trees contact power lines. The state is also historically prone to intense droughts that dry out forests.
Standard wood sided homes with a shake roof are easily burned by wild fires. Homes can, however, be built to be highly fire resistant through the use of non-flammable roofing and non-flammable siding and deck material. This is in addition to keeping clear the area around the home, and using detached garages and shops (a frequent source of accidental fire starts).
When wildfire swept through Bob Heath’s neighborhood in Napa, Calif., a lot of other homes in the fire’s path burned to the ground. In recent years, as many as 2,000 homes (annually) have been destroyed by wildfire, a loss inflated by drought conditions in both eastern and western states, along with steady encroachment of development onto “frontier” lands.Jim Smalley, manager of wildland fire protection for the National Fire Protection Association (NFPA), notes that some home builders have taken an active role in fire prevention–often getting some perks in the process.
Source: How to Build Fire-Proof Homes | Builder Magazine
A major reason that wild land fires seem worse is the same reason hurricane damages seem worse – as documented by researchers and the insurance industry, more people are living in more expensive structures in locations that are historically prone to “natural disasters”. Damages are up because we are wealthier and build more, nicer buildings in these zones, not because of an increasing incidence of events.
There are solutions. In hurricane prone areas near the ocean, new homes are built on risers with the bottom floor being a garage, storage and recreational area with “break away” walls to accommodate a storm surge.
In tornado prone areas, new construction uses steel fastening straps – or even steel stud construction – to create buildings that can survive the high winds of severe thunderstorms and tornadoes.
Logically, fire prone zones should be using fire resistant construction techniques.
Update – a day after writing this, the SF Chronicle had a report saying much the same, and adding that roof vents are an important weakness in fire resistance as wind blown sparks get sucked into attics.