Four fire engines and around 25 firefighters were called to a fire at a house conversion of two floors used as sheltered accommodation in Southbury Avenue in Enfield.
The first floor was destroyed by fire. Half of the stairwell leading to the loft was damaged by fire. Three people left the premises before the arrival of the Brigade.
The Brigade was called at 2342 and the fire was under control at 0053. Fire crews from Enfield and Edmonton fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.