Firefighters responded to a structure fire at 14 Ivy Lane at about 6:40 p.m., according to the Marin County Fire Department.
Arriving units found a detached garage fully engulfed in flames, with fire spreading to the adjacent home.
The fire was quickly extinguished, but not before it destroyed the garage and caused significant damage to the primary residence, officials said.
No one was injured.
The fire displaced four residents, and power in the area was temporarily disrupted.
The cause remains under investigation.