The 7,429-square-foot addition is expected to open in the summer of 2010 to help the growing patient volume. Currently, St. Clair performs more than 11,000 surgeries a year in 11 main operating rooms.

That volume is expected to increase for the foreseeable future.

The hospital said three new operating rooms will be added, while an existing smaller operating room will be eliminated, resulting in a net increase of two ORs. The total number of main operating rooms will rise to 13.

Each new OR will be equipped with state-of-the-art technology, including operating equipment and flat panel monitors mounted to the ceiling via "booms," which allow for easy access to and return of equipment.

The hospital said it does not anticipate any interruption of surgical procedures in the existing ORs during construction.

Because the staging area for construction is near the entrance to the emergency department, the hospital is offering free valet parking service for patients and visitors to the emergency room. Signs are posted near the ER entrance to direct drivers to the valet service that is available 24/7.