Firefighters tackled a blaze at a disused listed building in Broomfield Park, Southgate.
Part of the ground floor of the three storey building was damaged by the fire.
The Brigade was called at 0537 and the fire was under control by 0801. Fire crews from Southgate, Finchley and Hornsey fire stations attended the incident.
The cause of the fire is under investigation by London Fire Brigade and the Metropolitan Police.