Ten fire engines and around 70 firefighters responded to a fire in a disused church hall on St Andrews Road in Romford.
Part of the ground floor, first floor and the building's roof was damaged by the fire. There were no reports of any injuries.
One of the Brigade's 32m ladders was deployed to the scene, allowing crews to attack the fire from above.
The fire produced a large amount of smoke and residents in the area were advised to keep doors and windows closed as crews responded.
The Brigade was called at 0030 and the fire was brought under control by 0227. Firefighters from Dagenham, Ilford, Hainault and surrounding fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and Metropolitan Police.