Method comprises mounting at least one standard steel shipping container on a weight-bearing foundation at the ends thereof. Where two or more containers are used, the containers may be in spaced and/or abutting side-by-side relationship; and/or may be mounted one upon another. Where containers are mounted side-by-side, portions of the inner sidewalls are removed leaving at least narrow flanges extending inwardly from the edges thereof. A roof is installed over the top walls of the containers; a raised floor is installed over the bottom walls of the containers enclosing flanges that extend inwardly from the bottom walls; and a dropped ceiling is installed under the top walls of the containers enclosing flanges that extend inwardly from the top walls. At least one window opening and one door opening are provided in the side and end walls, and a window and a door are installed therein. The invention includes the novel product of the method.