A building framework includes plural column assemblies interconnected by plural full-length beam assemblies, with the union of the column assemblies and beam assemblies forming beam-to-column joint assemblies according to this invention. The column assemblies include pairs of side plates spanning the column members of the column assemblies and projecting toward another column assembly of the plurality of such column assemblies. The full-length beam assemblies include beam members for being received between column assemblies to be interconnected and defining an end gap with respect to each column member. Additionally, the full-length beam assemblies include at each opposite end portion thereof a pair of cover plates, including an upper cover plate and a lower cover plate, which cover plates are sized and configured to be united with the side plates of a column assembly, as by welding applied at a construction site. The full-length beam assemblies may also include provisions for drawing together the side plates of a column assembly preparatory to welding, which side plates are sufficiently spaced apart to provide a “rattle” space allowing entry of an end portion of a full-length beam assembly between the side plates as a step in the erection process for the framework.