Four fire engines and around 25 firefighters were called to a house fire on Highfield Road in Purley.
Half of the roof of the semi-detached property was damaged by fire. Two adults and four children left the house before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 1811 and the fire was under control by 1938. Firefighters from Purley, Croydon, and Wallington fire stations attended the scene.
The fire is believed to have been accidental and caused by a bathroom extractor fan.