Kawerau Netball Centre was "well alight" by the time fire crews arrived at the scene.
A Fire and Emergency spokesman confirmed fire crews from Edgecumbe, Kawerau and Rotorua were called to help fight the structure fire on Plunket St around 8.08pm yesterday.
He said the fire was contained to the basement at a size of 20 by 10 metres.
There were no reports of injuries.
The fire investigator is heading to the scene this morning to determine the cause.
