When the Civil Engineering Building opened in 1983, it didn’t rise from the ground—it disappeared into it. In the elevator, you’ll notice the buttons are reversed: ground level at the top, seven at the bottom. (The fourth and fifth floors? Solid limestone.) If you want to skip the elevator, there’s an inside stairway that descends 110 feet. Only 5 percent of its 150,000 square feet is visible at the surface.

The American Society of Civil Engineers gave the structure the Outstanding Civil Engineering Achievement award in 1983.

Designed by architect David J. Bennett, a U of M grad and later a professor of architecture, the building’s subterranean plan maximized energy efficiency and took advantage of what’s always a hot commodity on an urban campus: space. Bennett, who died last year at age 89, was also responsible for Williamson Hall, another largely underground building on campus.

Some technology and construction techniques used on the Civil Engineering Building may have been a bit ahead of their time, as maintenance proved challenging over the years, including water damage in the subsurface levels and a disconnected drainage system. The architecture firm Miller Dunwiddie was brought in to make improvements: a new roof, wall flashing, a vapor barrier, masonry repairs, and reactivation of the water-diversion system. The building is slated to receive more improvements—keeping this one-of-a-kind building standing, or rather descending, for the next generation.