Crews were called at around 11.51 to a fire on Hammond Street in the Richmond Hill area of Leeds.
It is thought that some polystyrene on an unfinished house on a building site caught fire - sending large amounts of black smoke billowing into the air.
There is still one fire pump at the scene, which is expected to remain there for some time, according to West Yorkshire Fire Service.
There was also a fire reported at Cottingley Towers in Leeds. You can read about that incident here.