Six fire engines and 35 firefighters and officers have been called to a fire on Nether Street in North Finchley this afternoon.
Part of the first floor and roof is alight in a two floored semi-detached house which has been converted into flats. One person left the property before the Brigade arrived.
The Brigade was called 1211 and fire crews from Finchley, Barnet, Hendon and West Hampstead fire stations are at the scene.
The cause of the fire is not known at this stage.