Four fire engines and around 25 firefighters were called to a house fire on St Joseph's Drive in Southall.
Half of the loft in a mid-terraced house was damaged by the fire. Five people left the building before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 1423 and the fire was under control by 1600. Fire crews from Southall, Ealing, Hayes and Hillingdon fire stations were at the scene.
The cause of the fire is believed to be a light left on in the loft space which set light to nearby combustible items.