Four fire engines and 21 firefighters and officers were called to a terraced house fire in Well Road, Barnet.
Most of the first floor and a small part of the roof was damaged by fire. The roof of an adjacent property was also slightly damaged in the blaze.
The Brigade was called at 1034 and the fire was under control at 1235. Fire crews from Southgate, Finchley, Hendon, and colleagues from Hertfordshire fire stations attended the scene.
The cause of the fire is under investigation.