The Autumn sun is believed to have caused a house fire on Hookstone Way in Woodford Green, prompting a safety warning from firefighters.
The first floor of the house was destroyed by the fire and a small section of the roof was also damaged.
The Brigade's fire investigation team believe the most likely cause of the blaze was sunlight refracting on perfume bottles and igniting bedding.
Fire Investigation Officer Paul Osborne said: "We believe the sunlight came through the window and refracted off some perfume bottles which were being stored by the bed and then set light to the bedding.
"Fires caused by sunlight are not as rare as you might think. At this time of year particularly, and in the spring, the sun generally tracks low in the sky and because of that, the light going in through windows will stick on one point for a long period of time.
"You only need something such as a glass ornament or jar to focus the sun's rays and it can ignite textiles.
"It's not so much about the temperature but about the strength of the sunlight.
"Our advice is to make sure that you keep mirrors, crystals, glass ornaments and other reflective items out of direct sunlight at all times.
“It’s never a good idea to try and tackle a fire yourself, it’s much safer to get out and call 999 and let firefighters deal with it.”
The Brigade was called at 1440 and the fire was under control at 1536. Four fire crews and around 25 firefighters from Woodford, Walthamstow, Hainault, and Leytonstone fire stations attended the scene.