A 36-year-old man has been arrested on suspicion of arson with intent to endanger life.
The fire badly damaged a bungalow in St Micheals Road in Tilehurst, Berkshire, on Monday morning.
No-one was injured in the incident.
The man was arrested at about 0100 BST on Monday and remains in custody.
Experts are still working at the scene to try and determine the cause of the fire.