Twenty fire engines and around 125 firefighters tackled a fire on Newsholme Drive in Southgate.
Three flats in the loft space of a three-storey building that has been converted into flats were destroyed by fire. Half of the building's roof was also damaged. There are no reports of any injuries. Around 50 people left the building before firefighters arrived.
The Brigade's drone team provided an aerial view of the fire to help the Incident Commander tackle the fire while a 32-metre turntable ladder was used to extinguish the flames.
Crews wearing breathing apparatus spent a number of hours working to bring the fire under control before dampening down to ensure the scene was safe.
The Brigade was called at 2130 and the fire was brought under control by 0151. Crews from Southgate, Edmonton, Enfield, Tottenham, Hornsey, Finchley and surrounding fire stations attended the scene.
The cause of the fire is under investigation.