O’FALLON, ILL. — Swansea, Ill.-based Holland Construction Services has completed construction of the $3.7 million expansion for O’Fallon School District #203, which will eliminate overcrowding at O’Fallon Township High School. The expansion includes seven classrooms, new chemistry labs and 1,000 square feet of administrative offices. Wm. B. Ittner served as the architect for the project. Holland Construction and Ittner are also working together on the $37 million O’Fallon Township High School Millburn Freshman Campus expansion, which is currently under construction.