Four fire engines and 21 firefighters and officers were called to a fire at a railway arch being used as a vehicle repair workshop in Sigdon Passage, Hackney.
Most of the workshop was damaged by the fire. There were no reports of any injuries.
The Brigade was called at 0209 and the fire was under control at 0317. Fire crews from Homerton and Stoke Newington fire stations attended the scene.
The cause of the fire is under investigation by the Metropolitan Police Service.