St. Paul Academy and Summit School (SPA) announced plans Tuesday for a new math and science center to be made possible by a $15 million gift from a member of the Class of 1943.

Hugh Schilling, 91, still serves as chairman of the board of Horton Holding Inc. of Roseville and, according to SPA, his $15 million gift is the largest single donation ever to an independent school in Minnesota.

“We are grateful and humbled by Hugh’s generosity in making this gift, and appreciative of his vision of SPA as the premier high school for educating Minnesota’s future scientists and engineers,” SPA Head of School Bryn Roberts said in a statement.

Roberts announced the gift during a morning assembly attended by Schilling, who received a standing ovation from students.

The Hugh K. Schilling Math and Science Center is to be built along Davern Street on SPA’s Randolph Campus, which is home to its Middle and Upper schools. A 1928 building will be demolished to make room for the center, which is to be connected to the school’s original building, Old Main, by a two-story glass passageway.

SPA said that the center will be a “state-of-the-art math, science, engineering and computer science facility.”

Construction is expected to begin in April and be finished in August 2018.

Schilling studied engineering at the University of Minnesota and is the holder of many patents, according to SPA. He founded Horton, a manufacturer of fan drives, fans and suspension products for on- and off-highway vehicles and equipment, and also served as chairman of the Metropolitan Airports Commission in the early 1990s, appointed by former Gov. Arne Carlson.

The Schilling center is being envisioned as the “signature piece” of a multiyear renovation of the Upper School, a project that is expected to cost a total of $38 million. A capital campaign is underway.