Four fire engines and around 25 firefighters were called to a fire at a house on Crawford Avenue, Wembley.
Part of the ground floor of the property was damaged by fire. Two people left the building before the arrival of the Brigade.
The Brigade was called at 0408 and the fire was under control at 0507. Fire crews from Wembley and Northolt fire stations attended the scene.
The cause of the fire is under investigation.