Four fire engines and around 25 firefighters tackled a fire at a house on Sedley Grove in Harefield.
Most of the ground floor of the semi-detached house was damaged by the fire. One man left the building before the Brigade arrived and was taken to hospital by London Ambulance Service.
The cause of the fire is under investigation.
The Brigade was called at 1246 and the incident was over for firefighters at 1412. Crews from Hillingdon and Ruislip fire stations attended the scene alongside a crew from Buckinghamshire Fire and Rescue Service.