Six fire engines and around 40 firefighters attended a fire on Kingston Road in Ilford.
Part of the roof of a single-storey church was damaged by fire. A single-storey rear outbuilding was destroyed by fire. Part of the external fascia of a nearby end-of-terraced house was also damaged along with garden fence panels.
Around seven people, who left a nearby building, were treated for smoke inhalation, with two taken to hospital by London Ambulance Service as a precaution.
The Brigade's Control Officers received around 14 calls about the fire.
The first call was received at 2303 and Control Officers mobilised crews from Ilford, Barking, Plaistow, Stratford and Leytonstone fire stations to the scene. A 32-metre turntable ladder from Greenwich Fire Station also attended. The fire was brought under control by 0043.
The cause of the fire has been recorded as undetermined.