Four fire engines and around 25 firefighters were called to a fire in a conservatory at the rear of a house on Grove Road in Hounslow.
Half of the conservatory was destroyed by fire at the semi-detached two storey house.
Four residents left the property before the Brigade arrived and no injuries are reported.
The Brigade was called at 1004 and the fire was under control by 1055. Fire crews from Heston and Feltham fire stations were in attendance.
The cause of the fire is under investigation.