Four fire engines and 21 firefighters and officers were called to a fire at a house in Merton Hall Road in Wimbledon Chase.
Approximately half of the loft space and roof was damaged by fire.
Two women left the property before the arrival of the Brigade. There were no reports of any injuries.
The Brigade was called at 1950 and the fire was under control at 2247. Fire crews from Wimbledon, New Malden, Mitcham and Tooting fire stations attended the scene.
The cause of the fire is under investigation.