A unitary structure defining a plurality of internal occupiable spaces, the unitary structure comprising: a plurality of adjacent modules (301, 311, 312, 313, 314) arranged vertically and horizontally adjacent to each other, each of the plurality of adjacent modules (301, 311, 312, 313, 314) having at least one occupiable space; an interlocking plate arranged to span horizontally across and couple horizontally adjacent modules, at least one binding member arranged to span vertically across and couple vertically adjacent modules,; and wherein each of the plurality of adjacent modules (301, 311, 312, 313, 314) further comprises a plurality of structural panels (302, 303, 304, 305, 306, 307), each of the plurality of structural panels (302, 303, 304, 305, 306, 307) are assembled with adjacent structural panels (302, 303, 304, 305, 306, 307) by a plurality of mechanical connectors, wherein at least one edge of one module is aligned with a corresponding edge of the adjacent modules, and peripheral connection edges of the structural panels (302, 303, 304, 305, 306, 307) are shaped to allow a single positional engagement, held in place by connections having dowelling or bolts; and wherein the binding member comprising a first rod arranged to be inserted through at least one edge of a lower-level module, and a second rod arranged to be inserted through at least one edge of an upper-level module, the first and second rods comprise an internally threaded end and an externally threaded end, the internally threaded end and the externally threaded end are arranged to be complementary with each other, wherein the externally threaded end of the second rod is arranged to be inserted into the internally threaded end of the first rod, and characterized in that the interlocking plate includes a main plate having a plurality of openings and guide projections arranged on the main plate and at least partially around the openings, wherein each of the guide projections comprises an upper and a lower portion provided on opposite sides of the main plate; wherein the interlocking plate is interposed between the upper-level module and the adjoining lower-level module, wherein an internally threaded socket head of the first rod is fitted within one of the plurality of openings and the upper and lower guide projections to prevent lateral or horizontal movement of horizontally adjacent modules. a plurality of adjacent modules (301, 311, 312, 313, 314) arranged vertically and horizontally adjacent to each other, each of the plurality of adjacent modules (301, 311, 312, 313, 314) having at least one occupiable space; an interlocking plate arranged to span horizontally across and couple horizontally adjacent modules, at least one binding member arranged to span vertically across and couple vertically adjacent modules,; and wherein each of the plurality of adjacent modules (301, 311, 312, 313, 314) further comprises a plurality of structural panels (302, 303, 304, 305, 306, 307), each of the plurality of structural panels (302, 303, 304, 305, 306, 307) are assembled with adjacent structural panels (302, 303, 304, 305, 306, 307) by a plurality of mechanical connectors, wherein at least one edge of one module is aligned with a corresponding edge of the adjacent modules, and peripheral connection edges of the structural panels (302, 303, 304, 305, 306, 307) are shaped to allow a single positional engagement, held in place by connections having dowelling or bolts; and wherein the binding member comprising a first rod arranged to be inserted through at least one edge of a lower-level module, and a second rod arranged to be inserted through at least one edge of an upper-level module, the first and second rods comprise an internally threaded end and an externally threaded end, the internally threaded end and the externally threaded end are arranged to be complementary with each other, wherein the externally threaded end of the second rod is arranged to be inserted into the internally threaded end of the first rod, and characterized in that the interlocking plate includes a main plate having a plurality of openings and guide projections arranged on the main plate and at least partially around the openings, wherein each of the guide projections comprises an upper and a lower portion provided on opposite sides of the main plate; wherein the interlocking plate is interposed between the upper-level module and the adjoining lower-level module, wherein an internally threaded socket head of the first rod is fitted within one of the plurality of openings and the upper and lower guide projections to prevent lateral or horizontal movement of horizontally adjacent modules.