A floor or roofing building structure (S) is described, including a plurality of intercommunicating roofing modules (M) arranged side by side; a connecting reinforcement (R) arranged between the modules (M); and a binder material matrix (X) adapted to embed the roofing modules (M) and the connecting reinforcement (R) so as to form a self-supporting monolithic structure. Each roofing module (M) comprises a housing volume (V) adapted to receive at least one functional element (F) of the structure (S), which is laterally defined by a wall (W), which has at least one communication opening (A) adapted to be joined in continuity to a corresponding opening (A) defined on the side wall (W) of an adjacent module (M) through an associated operative channel (C), and is superiorly and inferiorly defined by a pair of removable base elements (T, B) arranged to close the housing volume (V), which are accessible from opposite sides of the structure (S).