The blaze was reported at 3:30 p.m. at 224 Calle Marguerita, Santa Clara County fire Investigator Jeremy Davis said.
Stain material left beside the house spontaneously combusted due to the heat, lighting the outside of the house before the flames spread to the attic, according to Davis.
A firefighter suffered a knee injury and was sent to a hospital for treatment. Davis did not know the firefighter's condition today.
Firefighters were able to save a dog and its puppies by confining them to a shed in the backyard, he said. The residents were not home.
The fire caused an approximate $500,000 in damage to the structure and contents. The house was uninhabitable after the blaze.
Davis said to prevent stain materials, such as rags or brushes, from spontaneously combusting, the materials should be soaked in a bucket of water for 24 hours after their use and then laid out flat to air dry.