Fire Chief Robert Sinnott said the fire at 228 Madrone Ave. in Larkspur was reported at 11:45 a.m.
Flames were rising 20-30 feet above the roof when firefighters arrived, Sinnott said. No one was home at the time.
The blaze was confined to the house and no other homes were damaged, Sinnott said.
The house is in an open space area and firefighters were concerned about an ember shower igniting vegetation fires.
No injuries were reported, Sinnott said.