Firefighters were called to a fire at a detached chalet bungalow on Highfield Drive in Ickenham.
Part of the first floor and the roof of the two-storey building was damaged in the blaze.
A smoke alarm sounded and woke the resident. A man left the building, uninjured, before the Brigade arrived.
The Brigade’s Fire Investigators believe the fire to be caused by an electric light in the roof structure.
Station Officer, James Bowler who was at the scene, said
“Firefighters worked hard to tackle the roof fire to prevent it from spreading to neighbouring properties.
“The smoke alarm did its job and warned the occupant that a fire had broken out. It is vital that you have working smoke alarms in every room where a fire can start, for example any room where appliances are plugged in, plus a heat alarm in the kitchen and the bathroom.”
The Brigade was called at 0013 and the fire was under control by 0126. Fire crews from Ruislip, Hillingdon and Northolt fire stations were at the scene.