Abstract: A method and a design system for designing or constructing new parts of a design unit, in the context of a design-space environment made of already existing parts of the design unit, includes at least one CAx system and at least one central data base, which are interconnected by a data circuit. To permit new parts to be designed or constructed in a simplified, cost-effective, and timesaving manner, a design space for the design of the part is defined in the CAx system by a user and copied to the central data base. In the central data base, all of the already existing parts of the same design unit are ascertained, which, or whose design spaces, come in contact with the defined design space. The ascertained parts are copied completely, or in detail form, as a design-space environment, to the CAx system and represented in the correct position relative to the defined design space for designing the part.