The permit holder, identified by WVIT as a 46-year-old woman, was trying to back into a parking spot at the Waterbury office when she accelerated instead of braking, plowing through the windows facing the lot, according to Connecticut State Police.
Two customers inside the building reported minor injuries and one person was taken to the hospital, police said.
The driver and the DMV inspector administering the test were not injured.
The landlord for the DMV offices at 2210 Thomaston Avenue immediately responded and closed up the window and addressed the building damage.
There were no interruptions to DMV services.