Four fire engines and around 25 firefighters have been called to a fire at a house on Fortune Avenue in Edgware.
Part of the second floor was destroyed by fire.
The Brigade was called at 2352 and the incident was over by 0055. Fire crews from Stanmore, Mill Hill, Hendon and West Hampstead fire stations were in attendance.
The cause of the fire is under investigation by the Met police and the Brigade’s fire investigation team.