Four fire engines and around 25 firefighters were called to reports of a shed alight on Green Lanes in Hornsey.
A garden shed and a fence at the rear of a terraced house converted into flats were destroyed by fire. Part of a five-roomed flat on the lower ground floor of the building was also damaged by the blaze. Three adults and one child left the building before the Brigade arrived. There were no reports of any injuries.
The Brigade's 999 Control Officers took 14 calls to the blaze.
The Brigade was called at 1309 and the fire was under control by 1404. Fire crews from Holloway, Stoke Newington and Tottenham fire stations attended the scene.
The cause of the fire is under investigation.