A conformable modular support/enclosure wall system incorporates a skin formed of modular sheet sections bolted to a skeleton or framework constructed of elongate rib elements that can be fastened, e.g. bolted, together in various relationships including end-to-end, side-to-end and side-to-side configurations. The rib elements are provided in a variety of lengths and wall arrangements and each element has a generally trapezoidal cross-section, with a similar trapezoidal appearance in side elevation. The rib elements include transverse slots and apertures as well as axial apertures all configured to receive bolt fasteners within a range of angular orientations relative to the axial and transverse axes of the ribs. The flexible sheet sections of the skin bear arrays of openings in the form of elongated slots arranged in coordinate grid patterns, with the slots alternately aligned with the x and y axes of the same or independent coordinate grids. Threaded hanger bars extending through one or more skin sections and through the slots and apertures in the ribs, serve to secure the skin to the ribs, using mating nuts threaded onto the hanger bars. Separate rib bolts extending through the slots and apertures in the ribs serve to secure the ribs to each other to form a skeleton or framework using rib nuts threaded onto the rib bolts.