American land-use reformers intent on addressing present-day housing shortages have, for the last decade, focused their efforts on amending zoning codes—the very rules that gradually downzoned most urban land in the U.S., effectively outlawing multifamily housing, spurring suburban sprawl, and fanning the current crisis. Recently, however, a group of young architects and planners has brought attention to another code barrier that limits design options for large multifamily buildings: the multiple egress routes mandated by most American building codes. The argument, in short, is to re-legalize single-stair apartment buildings, also known as “point-access blocks”—a typology that was once commonplace and remains so in much of the world, including the European Union, where fireproof single-stair designs are allowed. If combined with zoning reform, such code reform would enable attractive, light-filled multifamily housing to be built cost-effectively on countless urban sites that would otherwise be developed as single-family homes.

Commentators often wonder why new apartment buildings across the United States tend to look alike, not-so-subtly implicating architects and developers. One key reason is that decisions around organization and massing are prescribed by, or strongly incentivized by, regulations. In the limited areas where zoning codes allow for apartments, these rules have given us the notorious “five over one.” In code lingo, these are a Type V light wood frame of up to five stories built over a single story of Type I fireproof podium (typically steel or concrete), with a double-loaded corridor and a stair at each end. Long, windowless corridors slice through the middle of deep floor plates. Non-corner units only have windows on one side, opposite the entry door—favoring studios and one-bedroom layouts.