With the objective of fostering the energy efficiency of the building sector as well as of the integration of renewable energy sources, the adoption of near Zero Energy Buildings ( nZEB) concepts (buildings that have a very high energy performance) in new and in existing buildings, is currently being promoted by the SouthZEB project. This Project, initiated in March 2014, is developing, in 30 months, certified training modules targeted towards engineers, architects, municipality technicians and decision makers in Southern European countries, including Portugal. Training modules definition considers the experience and know-how of the front-runner countries (Austria, UK and Northern Italy) participating in the project, but are also based on the counselling of representatives of the main nZEB stakeholders in each of the Southern European countries partnering the SouthZEB project (Portugal, Italy, Greece and Cyprus), the so-called SouthZEB National Support Groups. This paper, first, elaborates on the nZEB concept and its adoption evolution in Europe. Secondly, it focuses on the need for professional training, which has been a barrier encountered in nZEB progress in Southern European countries. Finally, the paper presents the certified training development methodology followed by the SouthZEB project, with a particular focus in the Portuguese experience.