Four fire engines and 21 firefighters and officers were called to a fire at a house in Beverley Gardens, Wembley.
Part of the ground floor, first floor and roof of a semi detached house were damaged by fire.
Two people left the property before the arrival of the Brigade. There were no reports of any injuries.
The Brigade was called at 1143 and the fire was under control at 1244. Fire crews from Stamore, Wembley and Park Royal fire stations attended the scene.
The cause of the fire is currently unknown.