Six fire engines and around 40 firefighters were called to a fire at a building under construction on Ashley Road in Tottenham Hale.
A store cupboard on the ground floor was destroyed by fire. There were no reports of any injuries.
The fire is believed to have involved an electric heater.
A London Fire Brigade spokesperson said: “Fires involving heaters like this are all too common. They usually start when items are placed too close to the heater and ignite.
“Before attempting to move or put away you heater, make sure you turn it off and allow it to cool down properly first. It’s also really important to make sure heaters are well maintained and in good working order.”
The Brigade was called at 2330 and the fire was under control by 0115. Fire crews from Tottenham, Stoke Newington, Hornsey, Leyton, Edmonton and Walthamstow fire stations attended the scene.