Six fire engines and around 40 firefighters attended a fire on Park View Road in Finchley.
The fire occurred at a semi-detached house converted into two flats. A loft and part of the roof was damaged by fire. There were no reports of any injuries.
The Brigade was called at 1433 and Control Officers mobilised crews from Finchley, Hornsey, Barnet and Hendon fire stations to the scene. A 32-metre turntable ladder from Tottenham Fire Station also attended and was deployed as an observation tower, providing the Incident Commander with a greater situational awareness of the incident.
The fire was brought under control by 1550.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police.