Abstract: A precast stackable tower shaft wall stair unit and method having four structurally interconnected opposing walls forming a peripherally defined body defining a medial channel extending therethrough. A locking recess is defined in one corner portion at adjacent interconnected walls, and a mating locking protuberance is carried at a diametrically and vertically opposite corner portion allowing units to be stacked upon one another forming a continuous medial channel extending therethrough. A lower landing, an upper landing and a flight of stairs extending between a lower landing and an upper landing are carried on a wall in the medial channel extending from the lower edge to an upper edge. Stacking of adjacent to units simultaneously forms a medial channel extending therethrough and a continuous stairway therein.

Abstract: A precast stackable tower shaft wall stair unit and method having four structurally interconnected opposing walls forming a peripherally defined body defining a medial channel extending therethrough. A locking recess is defined in one corner portion at adjacent interconnected walls, and a mating locking protuberance is carried at a diametrically and vertically opposite corner portion allowing units to be stacked upon one another forming a continuous medial channel extending therethrough. A lower landing, an upper landing and a flight of stairs extending between a lower landing and an upper landing are carried on a wall in the medial channel extending from the lower edge to an upper edge. Stacking of adjacent to units simultaneously forms a medial channel extending therethrough and a continuous stairway therein.