The blaze was reported at 12:54 a.m. at a home on the 500 block of Monte Diablo Avenue, according to San Mateo fire Battalion Chief Joe Novelli.
Arriving firefighters found a fire in the rear of a two-story home at 515 Monte Diablo Ave., Novelli said.
Crews from the San Mateo, Central County and Foster City fire departments conducted searches of four nearby buildings and managed to contain the blaze to the home where it started, he said.
The fire was extinguished within seven minutes while the building's 18 occupants were safely evacuated. No injuries were reported.
The cause of the fire is still under investigation, and Novelli said it caused an estimated $65,000 in damage with slight smoke damage to a neighboring structure at 517 Monte Diablo Ave.