Four fire engines and 21 firefighters and officers dealt with a maisonette blaze on Polecroft Lane on Forest Hill.
Half of the split level maisonette was damaged by the fire. An adult and a child left the building before the Brigade arrived.
The Brigade was called at 1203 and the fire was under control by 1300. Fire crews from Forest Hill, Lewisham, Beckenham and West Norwood fire stations attended the scene. The cause of the fire is under investigation.