Four fire engines and 21 firefighters and officers were called to a fire at a house in The Oaks in Hayes.
Part of the ground floor, part of the first floor and half of the stairs 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 1029 and the fire was under control at 1135. Fire crews from Hillingdon, Hayes and Southall fire stations attended the scene.
The cause of the fire is under investigation.