The original two-story school was constructed in 1928 at a size of 29,780 square feet. The school and grounds comprise 8.5 acres.
Changes made to the original building include:
- 1970 – the learning center was renovated
- 1975 – an addition totaling 5,528 sq. ft.
- 1991 – three mobile classrooms were added with the connecting walkways
- 1996 – an addition of 8,600 sq. ft., including four classrooms, additional restrooms; the mobile classrooms were removed
- 1997 – nine second-floor classrooms were reconfigured to create eleven classrooms
- 1998 – one mobile classroom was added with connecting walkway
- 2004 – an addition totaling 16,100 sq. ft. and renovation of 24,000 sq. ft.
Monroe School was named a 2018 Green Ribbon School for its innovative efforts to reduce environmental impact and costs, promote better health, and ensure effective environmental education. Monroe was one of 46 schools across the country to receive the award and one of four in Illinois. Monroe has a decades-long commitment to environmental education through its "Living Classroom Learning Lab," now in its 23rd year. To learn more about the Living Classroom, click here. To read about all of Monroe's Green efforts, click here.