Fire units from Ventura city and county were dispatched to the home in the 400 block of Nevada Avenue just after 2 p.m.
Officials said they found the structure aflame but were able to contain it within 20 minutes.
The owners were not at home at the time of the fire and no injuries were reported.
Damage was estimated to be $150,000 to the structure and $100,000 to personal items inside the house.
The home suffered extensive damage to the garage and second floor as well as to the exterior on one side.
The fire appeared to have started on the exterior and spread into the home. However, the exact cause of the fire was under investigation.