The original school was constructed in 1958 as a six-classroom school. The one-story school and grounds comprise 8.9 acres. The building size is 41,123 square feet.
Elm has undergone several expansions to meet the growing needs of the Burr Ridge, Hinsdale and Willowbrook communities it serves. The current building contains nineteen classrooms in addition to the gymnasium and the Learning Center. Changes made to the original building include:
- 1966 – an addition totaling 5,494 sq. ft. (5 classrooms)
- 1975 – an addition totaling 8,680 sq. ft. (a new learning center, four classrooms and student restrooms)
- 1991 – two mobile classrooms were added with a covered walkway
- 1996 – an addition of 8,800 sq. ft. (four classrooms, special service rooms and additional restrooms); the mobile classrooms were removed
- 2005 – an addition totaling 4,500 sq. ft. and renovation of 41,000 sq. ft.