Prefabricated components for making floor slabs, floors and walls with exposed wood beams for small buildings comprising laminated panels (6) with at least two mutually opposite edges that are affected by longitudinal grooves (10); laminated wood beams (5) being provided in an upper region with coupling elements (7) for respective central metallic lattices (8) and with at least one supporting ridge for the ends of the panels (6) that have grooved edges (10); the beams (5), the lattices (8) and the converging grooved edges (10) being mutually coupled by casting conglomerate (13).