Four fire engines and around 25 firefighters were called to a fire at a house on Pegwell Street in Plumstead.
Half of the first floor and part of the roof of the mid-terraced house was damaged by the fire. Four people left the building before the Brigade arrived. One man was treated on scene for smoke inhalation by London Ambulance Service crews.
The Brigade was called at 0731 and the fire was under control by 0844. Fire crews from Plumstead, Bexley, East Greenwich and Erith fire stations were at the scene.
The cause of the fire is under investigation.