Four fire engines and around 20 firefighters and officers were called to a fire at a house in Braemer Road, Worcester Park.
Part of the ground floor and part of the first floor of the property were damaged by fire.
Three people left the property before the arrival of the Brigade.
The Brigade was called at 1750 and the fire was under control at 1845. Fire crews from Sutton, New Malden and Mitcham fire stations attended the scene.
The cause of the fire is believed to be accidental and due to the unsafe disposal of smoking materials.