Four fire engines and around 25 firefighters were called to a fire at a house on Mildred Avenue in Hayes.
The ground floor of a semi-detached house was destroyed by the fire and part of the first floor was damaged. One woman left the property before the Brigade arrived. She was treated at the scene for smoke inhalation and taken to hospital by London Ambulance Service crews.
A London Fire Brigade spokesperson said: "There were no working smoke alarms in the property.
“Homes need multiple smoke alarms or you won’t be properly covered. Ideal spots for smoke alarms include rooms where you leave electrical equipment running like satellite boxes, computers or heaters; any room where you smoke, and anywhere you charge your mobile or laptop.
“Kitchens should be fitted with heat alarms and all alarms in the home should be tested regularly."
The Brigade was called at 1002 and the fire was under control by 1129. Fire crews from Hayes, Heathrow and Hillingdon fire stations were at the scene.
The cause of the fire is under investigation.