"As underlined by the EU in the document ""Towards a Sustainable Europe"" (2018) and the following contributions by the Members of the Multi-Stakeholder Platform (2019), education systems are not yet able to transmit the necessary skills and knowledge to contribute to a sustainable development. Among the EU's key recommendations is the integration of Education for Sustainable Development (ESS) into school curricula, in order to enhance the role of educational institutions and its actors, including students, in achieving the goals set by the Agenda 2030 (UN, 2015).The project “CLASS - Choose to Learn Adopting Sustainability Standards” intends to develop an educational framework consistent with these objectives, integrating the economic, social (eg inclusion and human rights) and environmental (eg protection of natural resources) dimensions.The achievement of such a goal requires a profile reinforcement of the teachers, who must be increasingly able to use teaching and evaluation methods in order to create links between school and the real world, highlighting the social usefulness of learning.The activities will involve one high school for each of the 4 countries involved (IT, PR, FR and DE): they will participate in the activity planning and the testing of integrated educational paths, aimed at the inclusion and civic responsibility of the students. One class for each school (around 80 students in total) will test interdisciplinary curricula where ESS will be the cross-curricular theme, designed by teachers (40 in total) and operators / volunteers of Third Sector Organizations (1 for each school). 10 students for each class (at ESL risk or low performances) will be involved in extra-curricular voluntary activities in the same institutions, in order to enhance key civic and social skills.Methodologically, the project will refer to recent literature, such as the concept of Living School (O'Brien & Howard, 2016) and Educational Interconnection (Warner & Elser, 2015), which promote an education founded on a global, based-on-experience knowledge, that encourages students to establish a contact and a dialogue with the world.The teachers, in order to build an organic vision of ""education"" – not only linked to skills and knowledge, but also aimed to raise awareness of universally shared needs and values – will be called to design and test new teaching methods, such as Solution-Based Learning and Real World Learning, moving from a transmissive to a transformative approach, where knowledge is co-constructed within the social context.At the same time, new assessment tools will be designed and tested, able to detect both formal and informal learning, not only related to the contents learned but -above all- related to the learning process, stimulating students to ""learn to learn"". The evaluation methodology proposed in the new educational paradigm, thus intends to integrate the standard assessment based on grades and tests with a fluid and dynamic evaluation, based on the recognition and empowerment of inclusive and positive behaviors.The project long-term results will be the re-design of school curricula, in order to make room for the ESS as a transversal theme, creatively and innovatively linking school subjects and sustainable development objectives. The expected impact is the opening of traditional curricula to the real world in order to create real changes, capable of improving the socio-cultural reality (Eflin & Sheaffer, 2006).The construction of new educational networks, experimenting collaborations between schools and Third Sector Organisations, will make it possible to enhance volunteering as a facilitator for the transfer of school-learned knowledge / skills to socially challenging extra-school contexts. The expected result for students and teachers is a greater awareness of Sustainability, as a holistic and multidimensional concept.The ultimate aim, which will ensure the sustainability of the CLASS project, is to stimulate a bottom-up multi-sector and multi-level dialogue and comparison process, to propose ""evidence-based"" educational policies valid both at national and European level, capable of triggering a virtuous process that has a positive impact not only on the quality of European education systems but also on the Third Sector Organisations ,that are involved in the construction of a more sustainable future."