Four fire engines and around 25 firefighters were called to a fire at a house on Salmon Street in Hendon.
Part of the ground and first floors of a detached house were damaged by fire and the roof was destroyed by the blaze. There were no reports of any injuries.
The Brigade was called at 1753 and the fire was under control by 1917. Fire crews from Hendon and Stanmore fire stations attended the scene.
The cause of the fire is under investigation.