Four fire engines and around 25 firefighters were called to a fire at a house on Tithe Barn Way in Northolt.
Part of the roof of a terraced house was damaged by the fire. There were no reports of any injuries.
The Brigade was called at 1301 and the fire was under control by 1350. Fire crews from Northolt, Hillingdon, Heathrow and Harrow fire stations were at the scene.
The Brigade's Fire Investigators believe the fire was accidental and involved a solar panel.