Modular fabrication of structures

A method of manufacturing a portable building structure, the method comprising:

• connecting a first plurality of steel structural members to form a rigid base assembly, said rigid base assembly providing an upper frame surface for supporting flooring panels and comprising floor mating features accessible from a top side of the rigid base assembly;
• connecting a second plurality of steel structural members to form a rigid roof assembly, said rigid roof assembly comprising roof mating features accessible from a bottom side of the rigid roof assembly, wherein each mating feature comprises mating projections extending perpendicularly from opposing sides of the rigid base assembly and the rigid roof assembly, each of the mating projections being configured to receive discrete steel posts therein;
• galvanizing the rigid base assembly, the rigid roof assembly and the steel posts such that the rigid base assembly, the rigid roof assembly and the steel posts are coated with a galvanized layer;
• connecting the rigid base assembly to the rigid roof assembly via the steel posts using galvanized steel compatible adhesive to bond the steel posts to the rigid roof assembly and to the rigid base assembly, wherein each steel post is configured to mate with one of said floor mating features and one of said roof mating features, and wherein each mating feature aligns the steel posts relative to the rigid base assembly during curing of the adhesive, said steel posts being immobilized curing of the adhesive;
• attaching panels to the rigid base assembly and to the rigid roof assembly to form side walls;
• and
• attaching the flooring panels to the upper frame surface of the base assembly.