Terna defines the engineering standards for the plants connected to the grid. More specifically, it defines the construction standards and performance required of equipment, machinery and components of long-distance power lines and stations.

In terms of the construction of the plants, Terna prepares projects for constructing the authorised works. More specifically, it defines the need for external resources and the budget for the projects, establishing the working methods and technical specifications of components and materials to be used in the construction of new lines or stations, also adopting innovative methods. New plant construction is generally outsourced.