This building type -- known for its four levels of studio apartments stacked atop one layer of parking -- is ubiquitous in some parts of Chicago and, unfortunately, in some parts of urban California. (Unfortunately, since the ground-level supports have a way of snapping during earthquakes.) Today, we think of these as eyesores and grieve over the mansions that disappeared in their wake, but they are a peculiar reminder of the very different society that was postwar America. These cheap concrete frame and picture-window constructions sprouted in many lakefront neighborhoods, especially Lakeview and Edgewater, as three factors collided:

(1) a pent-up demand for studio apartments, which became fashionable as changing social norms made it acceptable for young men and women to live on their own, as residential hotels and rooming-houses became socially unacceptable, and as the baby boom created an unprecedented number of new households after a twenty-year construction drought. Today, studios have fallen out of fashion among singles who prefer the spaciousness of 1-BRs that would have fit entire families back in the day.

(2) cheap new construction materials and techniques, particularly reinforced concrete, air conditioning, and aluminum window frames, arriving at the same time that architectural modernism permeated the public imagination.

(3) the permissive new 1957 zoning ordinance, which projected that Chicago would grow to five million residents (from its already overcrowded 1960 peak of almost four million) and would require many new residences -- especially along the perpetually popular lakefront, which would be served by a new subway line. Their boundless optimism crashed and burned in the 1970s-1980s; instead of growing, the city's population plummeted by over a million, none of the new subway lines envisioned ever materialized, and much of the city's economic might trickled out to the suburbs or gushed to the Sunbelt, the Third World, and to super-dominant global cities.

In 1967, the City Council amended the zoning ordinance to ban all-studio buildings and construction of the 4 plus 1 ceased almost overnight.