Four fire engines and around 25 firefighters were called to a fire at an annexe property in Grove End Road, St John’s Wood.
A garage and a car were destroyed by fire and part of a first floor flat was also damaged in the blaze.
The Brigade was called at 1944 and the fire was under control at 2215. Fire crews from Paddington, Lambeth and Kentish Town fire stations attended the scene.
The cause of the fire is under investigation.