Fire and Emergency New Zealand staff are also on the scene.
A woman inside the building said she heard an "almighty bang".
"I came out and saw the couch had moved [in the waiting room] and then I saw the damage."
She said she then saw the car behind the couch had gone through the front of the building.
"We went outside and there was a bit of smoke so someone went and got a fire extinguisher. We are just glad no one was seriously hurt."
The man driving has been taken to Rotorua Hospital as a precaution and the woman passenger was visibly upset and was being supported by emergency services.