Eight fire engines and 58 firefighters and officers were called to a fire at a detached house under refurbishment in The Drive, Wimbledon.
Part of a second floor loft conversion was damaged by fire.
The Brigade was called at 1719 and the fire was under control at 2201. Fire crews from Wimbledon, New Malden, Wandsworth, Tooting, and surrounding fire stations attended the scene.
The cause of the fire is under investigation.