Single egress construction (often nicknamed single stair) refers to a style or policy of apartment construction wherein only one pathway of exit (egress) is provided, or required. In practice, single egress apartments are typically built surrounding a central core, comprised of a single elevator shaft and staircase.
The term is often used by housing advocates in North America, where most jurisdictions’ building code regulates single egress construction to a maximum of 2 storeys, unit windows notwithstanding. The typical rationale is to provide redundancy during fire evacuation.
Housing advocates argue that this restriction has the unintended consequence of prohibiting most appropriate and affordable forms of medium-density urban housing,[1] and perhaps ignores the intended issue of fire evacuation safety, as two staircase constructions typically necessitate larger parcels of land, smaller individual units, and longer central hallways connecting them.