The National Electric Grid Development Plan has a ten-years time validity and is yearly revised to update the whole set of interventions to be implemented on the national electric grid. Interventions are classified according to their character into strategic (identification of needs and possible macro-solutions), structural (localization of electric corridors) and implementation-oriented (definition of the feasibility belt for the electric line layout). The Plan assessment and approval are on the whole performed at the National level but the compulsory release of building permit is also on charge of Regions and Local bodies; this is the reason why it is necessary to define the relationship between National and Regional levels and the conditions allowing both decisional autonomy at a Regional scale and an overall evaluation of the Plan at a National scale.