Four fire engines and around 25 firefighters were called to a fire at a house on Blenheim Gardens in Brixton.
Half of the ground floor of a mid-terraced house was damaged by fire. There were no reports of any injuries.
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.
“As a minimum you should have smoke alarms on every floor - in the hallways and the rooms you use the most, plus a heat alarm in the kitchen and the bathroom. They should be tested regularly.”
The Brigade was called at 1754 and the fire was under control by 1838. Fire crews from Brixton, Clapham and West Norwood fire station attended the scene.
The cause of the fire is under investigation