Six fire engines and around 40 firefighters were called to a fire at a house converted into flats on Abercorn Place in St John's Wood.
A balcony on the fourth floor of a mid terraced house converted into flats was completely destroyed by fire.
The Brigade's Control officers received the first of six calls alerting them to the fire at 0434 and deployed fire crews from Paddington, West Hampstead, North Kensington and Euston fire stations. The incident was over by 0640.
The cause of the fire is undetermined, it's believed it could be due to an electrical event in an air conditioning unit.