Abstract: A modular building capable of being readily assembled and disassembled comprising rectangular base and roof frames each formed by two longitudinal beams and two lateral beams, the roof frame having a smaller periphery than the base frame. Four columns extend between corners of the base and roof frames, these columns being set back within the periphery of the base frame while having a periphery matching that of the roof frame. The building includes a floor panel having an outer periphery matching the periphery of the roof frame and being dimensioned to rest on inner edge portions of the base frame beams, a roof panel for resting on the roof frame and having an outer periphery at least as large as that of the base frame, and side and end wall panels dimensioned to fit between the base frame beams and the roof panel.