A green or sustainable building infrastructure comprising conjoining modular building segments. The purpose of the invention is to increase the precision, quality, and timing of building projects by allowing modular building segments to be constructed in an off-site controlled environment, transported, and quickly assembled on site. The conjoining modular building segments are prismatic box-like structures conjoined in a variety of configurations, each having at least three walls. The prismatic box-like structures are arranged and attached horizontally to create ceilings and floors, and they are arranged and attached vertically to create walls for the infrastructure. Some of the walls may be removed and the space inside each prismatic box-like structure is available for storage. The prismatic box-like structures may have certain dimensions, comprise specific materials, or be constructed or conjoined in specific ways.