One would not expect Niles West High School to be a model of sustainability. Located in Skokie, Illinois, the facility is more than 50 years old and at 612,000 square feet, it stands among the nation's largest high schools. Last winter, Niles West became one of the first five schools in the United States to achieve certification from the U.S. Green Building Council for Leadership in Energy and Environmental Design (LEED) for Existing Buildings: Operations & Maintenance (EB: O&M). A shaky economy has forced many school districts to tighten their purse strings. However, school administrators, teamed with an experienced consultant team, can still build a realistic plan for creating a sustainable model that improves operational performance, creates healthier learning environments, enhances curricula, and promotes environmental stewardship. Best of all, realizing all these benefits does not require constructing an expensive new school or knocking down a single wall. The Niles West story teaches a valuable lesson: if a massive 50-year-old high school building can achieve higher energy efficiency and save operational dollars, so can most other education facilities. Distilled from the Niles West experience, some of these considerations discussed in this paper will help districts make the most of what they have without spending a fortune.