Abstract: A set of modular blocks for the construction of buildings in general, specially designed to meet different situations arising during work execution. It comprises a standard block and various supplementary blocks which show, on their external side faces, straight longitudinal grooves arranged centrally, extending from one end to the other, and matching with a pass-through duct defined in an equidistant central section; supplementary blocks meet the same constructive criteria and are characterized by the combination of side extensions—equivalent to the thickness of each block—with middle section cuts to define split blocks, with flat supporting bases (which eliminate two of the legs), and with the side extension of the shorter section, the set being completed by the inclusion of supplementary blocks to serve as closing covers and anchorage caps.