Six fire engines and around 40 firefighters were called to a fire at a house on Belvoir Close in Mottingham.
Most of the ground floor and half of the first floor of an end of terraced house were damaged by fire. Three men left the building before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 0453 and the fire was under control by 0557. Fire crews from Eltham, Lee Green, Sidcup and Bromley fire stations attended the scene.
The cause of the fire is under investigation.