The Scottish Ambulance Service and Police Scotland were called to the scene shortly after 8am.
A spokeswoman for the ambulance service confirmed the driver of the van was transported to Royal Alexandra Hospital. His condition is not known.
The van is thought to have collided with the gym Fit for Life.
The A814 is currently closed between William Street and John Street and police are currently diverting traffic.
There are delays in both directions.
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