The International Scientific Conference on Buildings Energy Efficiency and Renewable Energy Sources was organised by the KNX Scientific Partner "TEI of Western Macedonia" in Kozani in Greece on the 1 st until the 3 rd of June 2014. This conference brought together engineers, researchers, organisations, students, authorities and industry from Europe and all over the world. More than 65 people attended the conference, which focused on the promotion of methods, products and services in the field of energy efficiency and renewable energy sources. KNX was the only solution that was presented emphasizing on the KNX city concept, which was explained to the audience by the System Engineer of KNX Association Mr. Vassilios Lourdas. Therefore, it was shown once again that KNX does not focus only on individual building control, but KNX is the platform to base a total integration of all the building systems from entire cities in order to achieve their sustainability and their energy efficiency.