Six fire engines and around 40 firefighters tackled a fire at a shop with dwellings above on Turner Street in White Chapel.
Half of a single storey extension to the four-storey building was damaged by the fire. There were no reports of any injuries.
No working smoke alarms were found in the property.
A London Fire Brigade spokesperson said: “This incident is a reminder of just how important it is to have working smoke alarms in your home. There were no smoke alarms fitted in the property. Smoke alarms give the earliest possible warning when a fire starts. We encourage everyone to have smoke alarms fitted in every room where a fire could start, plus a heat alarm in the kitchen. It’s important to test them regularly.”
The Brigade was called at 2302 and the fire was under control at 0106.
Fire crews from Whitechapel, Shadwell, Shoreditch and surrounding fire stations attended the scene.
The cause of the fire is under investigation.