Four fire engines and around 25 firefighters tackled a fire at a mid terraced house on Caithness Road in Mitcham.
Half of the first floor was damaged by the fire. Five people left the building before the Brigade arrived. There are no reports of any injuries.
Control Officers took the first of two calls at 1903 and mobilised crews from Mitcham, West Norwood and Tooting fire stations to the scene. The fire was extinguished by 2012.
The cause of the fire is under investigation.