At the conclusion of a visual flight rules flight, the pilot completed a practice instrument approach to the runway. When he decoupled the autopilot at the conclusion of the approach, he looked up and was momentarily blinded by the setting sun. When he regained sight, the airplane had drifted to the right of the runway centerline. The tower controller then advised him to execute a go-around, and the pilot added full power and held the nose level to gain airspeed before climbing. The airplane subsequently struck a construction barricade on a closed taxiway. The pilot continued around the airport traffic pattern and made a normal landing. As a result of the impact with the barrier, the airplane’s right wing was substantially damaged. The pilot reported that that there were no preimpact mechanical malfunctions or failures of the airplane that would have precluded normal operation.