From FIGS. 29 and 42, it can further be appreciated that cells, such as adjacent cells 428, 430, 432, and 434 may be open relative each other by virtue of the roof structure 34 being supported by the exterior wall posts and by central post formations 246C and 248A. Cells 436 and 438 may be closed off by interior wall assemblies for bedrooms or bathrooms or other living space.