Six fire engines and around 40 firefighters were called to a fire at a house on Thirlmere Gardens in Wembley.
Part of the roof of an end-of-terrace house was damaged by fire and a small part of the first floor was also damaged in the blaze. There were no reports of any injuries.
The Brigade was called at 1327 and the fire was under control by 1407. Fire crews from Wembley, Stanmore, Harrow, Park Royal and Northolt fire stations were at the scene.
The Brigade's Fire Investigators believe the fire was caused by hot works which were being carried out.