Four fire engines and around 25 firefighters tackled a fire at a house on Caverleigh Way in Worcester Park.
Half of the ground floor and a small part of the first floor and roof were damaged by the fire. An outside decking area was destroyed. A small part of the ground floor, first floor and roof of a neighbouring house were also damaged by the fire. There were no reports of any injuries.
The fire is believed to have been accidental and caused by the unsafe disposal of smoking materials.
A London Fire Brigade spokesperson said: “This incident serves as a reminder for smokers to fully extinguish their cigarettes before disposing of them.
“If you don’t, you risk causing a fire which could not only destroy properties, but also cost you your life.
“Firefighters recommend that you have a look at our online Home Fire Safety Checker to make sure there are no hidden hazards in your home.
"The online tool will ask you a series of questions that will help us work out the level of risk in your home, or the home of someone you care for. It only takes a few minutes to get tailored advice to keep yourself and loved ones safe from fire.”
Control Officers took the first of eight calls at 0958 and mobilised crews from Sutton, Mitcham and Kingston fire stations to the scene. The incident was over for firefighters at 1114.