A man was treated by paramedics after 35 firefighters fought to extinguish a blaze in Chalk Farm.
Six fire engines were sent to Princes of Wales Road as the first and second floors of a terraced house were gutted by flames.
Half of the ground floor was also damaged during the fire on Friday, which burned from 10.40pm to about 12.15am.
One man was treated at the scene by paramedics for smoke inhalation.
The cause of the fire is under investigation by the London Fire Brigade and the Metropolitan Police.
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