Four fire engines and around 25 firefighters were called to a fire at a house under refurbishment on Underhill Road in Southwark.
Part of the first floor of the semi-detached house was damaged. Six builders left the property before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 1559 and the fire was under control by 1743. Fire crews from Forest Hill, West Norwood, New Cross and West Norwood fire stations attended.
The Brigade's fire investigation team believe the cause of the fire was a halogen lamp coming into contact with a sofa and cardboard boxes.