Towns that lost their only school building that I am aware of, 2010-19:
Lineville, Stockport, Lost Nation, Menlo, Arcadia, Vail, Cincinnati, Crystal Lake, Lohrville, Mystic, Ringsted, Rippey, Ute, Denmark, Battle Creek, Hawkeye, Sabula, Titonka, Coggon, Walker, Boxholm, Clearfield, Dows, Elma, Manilla, Cleghorn, Corwith, Farragut, Gladbrook, Lime Springs, Pomeroy, Prescott, Stanwood, Bonaparte, Walnut, Ainsworth, Bernard, Grand Junction, Libertyville, Plainfield, Waterville, Everly, Elliott, Lewis, Mallard.
New (non-replacement) elementary schools, or grade fractions thereof, opened since 2010:
Iowa City, Waukee, Waukee, Ankeny, Iowa City, Waukee, Cedar Rapids (Prairie), Ankeny, Tiffin, Grimes, Solon, Waukee, Iowa City, Tiffin, Waukee.
That list does not count the new high schools that opened in Ankeny and Iowa City.
UPDATE: Thanks to a reader, added Solon, which went from two K-8 schools to three.