Cat. OG1 - Class. VIII: Civil and industrial buildings
Cat. OG2 - Class. V: Restoration and maintenace for real estate subjected to preservation.
Cat. OG3 - Class. VI: Streets, highways, bridges, flyovers, railways and underground railways.
Cat. OG6 - Class. III: Waterworks, gas pipelines, oil pipelines, irrigation and evacuation works.
Cat. OG11 - Class. IV: Technological systems.
Cat. OS21 - Class. II: Special structural works.
Cat. OS26 - Class. III: Special pavings and superstructures.