Six fire engines and 35 firefighters and officers were called to a house fire in Queenswood Avenue, Thornton Heath.
Most of a loft, half of the first floor and part of a timber-framed lean-to on the ground floor at the rear of the property were damaged by the fire. No injuries were reported.
The Brigade was called at 0950 and the fire was under control by 1039. Fire engines from Norbury, Croydon and West Norwood fire stations were at the scene.
The cause of the fire is under investigation.