Four fire engines and 21 firefighters and officers were called to a fire at a bungalow in Northlands Avenue, Orpington.
Part of the ground floor and part of the roof of the property was damaged by fire. Part of the roof of an adjacent bungalow was also damged in the blaze.
One woman was rescued by crews wearing breathing apparatus and was treated at the scene for smoke inhalation by London Ambulance Service crews.
The Brigade was called at 2256 and the fire was under control at 2327. Fire crews from Orpington and Bromley fire stations attended the scene.
The cause of the fire is under investigation.