Modular building roof-rim parapet structure

Gravity-stabilized modular and selectively unit-changeable and reconfigurable, parapet roof-rim structure comprising

• prepared, roof-rim gravity-docking reception structure disposed along and adjacent an elongate side of a building roof-structure perimeter, and constructed and arranged to receive and hold by gravity external structure which is lowered toward the reception structure, and
• modular, external parapet unit structure formed with plural, independent, modular parapet units, including angular corner units and linear non-corner units, constructed and arranged for complementary gravity docking with said reception structure, said units being lowerable by gravity in side-by-side unit adjacency toward conditions of unit-removable, gravity-stabilized disposition with respect to said reception structure, thus to form, collectively, a parapet roof rim along said roof-structure perimeter, said parapet roof rim including plural linear non-corner units disposed between pairs of angular corner units, and accommodating selective individual unit removal and replacement, thus to change the effective overall appearance of the parapet unit structure, wherein each external parapet unit structure includes a hook structure extending from an upper margin thereof for engaging said roof-rim gravity-docking reception structure and which further includes a locking structure extending through said hook structure and into said roof-rim gravity-docking reception structure, wherein said locking structure is thread-anchored in said roof-rim gravity-docking reception structure.