A construction system (10, 300, 400) for constructing a structure atop a foundation, the construction system (10, 300, 400) comprising: a rail assembly (20, 120), forming a track, wherein the rail assembly (20, 120) is configured to be mounted to the foundation, wherein the rail assembly (20, 120) comprises a first elongate rack comprising a plurality of axially adjacent teeth; a gantry (50, 350, 450) movably disposed on the rail assembly (20, 120), wherein the gantry (50, 350, 450) is configured to translate along a first axis relative to the rail assembly (20, 120), wherein the gantry (50, 350, 450) comprises a first driver configured to rotate a pinion gear that is engaged with the teeth of the first elongate rack to translate the gantry (50, 350 450) along the first axis relative to the rail assembly (20, 120); and a printing assembly (100, 200) movably disposed on the gantry (50, 350, 450), wherein the printing assembly (100, 200) is configured to translate along a second axis relative to the gantry (50, 350, 450), wherein the second axis is orthogonal to the first axis; and wherein the printing assembly (100, 200) is configured to deposit vertically stacked layers of an extrudable building material onto a top surface of the foundation to construct a structure, wherein the gantry (50, 350, 450) comprises: a vertical support assembly (60, 360, 460) movably coupled to the rail assembly (20, 120) with a plurality of rollers engaged with a track defined by the rail assembly (20, 120); and a trolley bridge assembly (80, 380, 480) movably coupled to the vertical support assembly (60, 360, 460) such that the trolley bridge assembly (80, 380, 480) is configured to translate along a third axis relative to the vertical support assembly (60, 360, 460); wherein the third axis is orthogonal to each of the first axis and the second axis; and wherein the printing assembly (100, 200) is movably coupled to the trolley bridge assembly (80, 380, 480). a rail assembly (20, 120), forming a track, wherein the rail assembly (20, 120) is configured to be mounted to the foundation, wherein the rail assembly (20, 120) comprises a first elongate rack comprising a plurality of axially adjacent teeth; a gantry (50, 350, 450) movably disposed on the rail assembly (20, 120), wherein the gantry (50, 350, 450) is configured to translate along a first axis relative to the rail assembly (20, 120), wherein the gantry (50, 350, 450) comprises a first driver configured to rotate a pinion gear that is engaged with the teeth of the first elongate rack to translate the gantry (50, 350 450) along the first axis relative to the rail assembly (20, 120); and a printing assembly (100, 200) movably disposed on the gantry (50, 350, 450), wherein the printing assembly (100, 200) is configured to translate along a second axis relative to the gantry (50, 350, 450), wherein the second axis is orthogonal to the first axis; and wherein the printing assembly (100, 200) is configured to deposit vertically stacked layers of an extrudable building material onto a top surface of the foundation to construct a structure, wherein the gantry (50, 350, 450) comprises: a vertical support assembly (60, 360, 460) movably coupled to the rail assembly (20, 120) with a plurality of rollers engaged with a track defined by the rail assembly (20, 120); and a trolley bridge assembly (80, 380, 480) movably coupled to the vertical support assembly (60, 360, 460) such that the trolley bridge assembly (80, 380, 480) is configured to translate along a third axis relative to the vertical support assembly (60, 360, 460); wherein the third axis is orthogonal to each of the first axis and the second axis; and wherein the printing assembly (100, 200) is movably coupled to the trolley bridge assembly (80, 380, 480).