Four fire engines and around 25 firefighters were called to a fire at a house converted into flats on Cromwell Road in Hounslow.
Most of the ground floor flat and a small part of the first floor flat was destroyed by fire.
One woman left the ground flat and a man left the first floor flat before the Brigade arrived
The Brigade was called at 1057 and the fire was under control by 1229. Fire crews from Heston and Feltham fire stations were at the scene.
The cause of the fire is under investigation.