This work seeks to identify the fundamental objectives behind the development of energy efficiency (EE) plans for countries. It also presents a method to quantify the degree of achievement of each objective, through the identification and operationalization of attributes. This was achieved by applying Keeney's value-focused thinking approach. For that purpose, three key decision makers in EE planning were interviewed along with a bibliographic review on the subject. From this process six fundamental objectives were identified formalizing the problem as a multi-objective one: (i) to minimize the influence of energy use on climate change; (ii) to minimize the financial risk from the investment; (iii) to maximize the security of energy supply; (iv) to minimize investment costs; (v) to minimize the impacts of building new power plants and transmission infrastructures and (vi) to maximize the local air quality. The respective attributes were: (i) CO2 emissions savings; (ii) payback; (iii) imported energy savings; (iv) investment cost; (v) electricity savings; and (vi) total suspended particles savings. To show the usefulness of the work, the objectives and attributes identified were used to show the possible outcomes from five hypothetical EE plans for Portugal. (c) 2012 Elsevier Ltd. All rights reserved.