These buildings are in almost every U.S. city. They range from three to seven stories tall and can stretch for blocks. They’re usually full of rental apartments, but they can also house college dorms, condominiums, hotels, or assisted-living facilities. Close to city centers, they tend toward a blocky, often colorful modernism; out in the suburbs, their architecture is more likely to feature peaked roofs and historical motifs. Their outer walls are covered with fiber cement, metal, stucco, or bricks.
They really are everywhere, I discovered on a cross-country drive last fall, and they’re going up fast. In 2017, 187,000 new housing units were completed in buildings of 50 units or more in the U.S., the most since the Census Bureau started keeping track in 1972. By my informal massaging of the data, well over half of those were in blocky mid-rises.