The board of trustees has approved a $108 million building project that would add at least 60 private patient rooms, a new emergency department and 225,000 square feet of space to Columbus Regional Hospital. Two phases of the project to build the five-story pavilion will begin this year, and completion is expected in 2011. Patient rooms will occupy the second and third floors of the pavilion. The fourth and fifth floors will be unfinished but could accommodate an additional 60 private rooms.