No one was injured in the fire, which was reported about 4 a.m. at a two-story residence in the 700 block of Ribera Drive, said Capt. David Sadecki, a department spokesman. The house is in an unincorporated area of the county off Cathedral Oaks Road.
Six fire engines, an air/light unit, and a ladder truck responding to the scene found heavy flames erupting from the garage area at the front of the house, Sadecki said.
Although the fire quickly spread to the second floor, crews had the blaze knocked down 50 minutes later, he said.
Sadecki said the American Red Cross Santa Barbara County will assist the eight displaced residents.
Crews will remain on scene throughout the morning overhauling the fire.
The cause of the fire is under investigation, and Sadecki said the home did not have working smoke detectors.