Our colleagues have also made significant efforts in the INTERREG V-A Program supported by the Hungarian-Croatian EE SUN (Energy Efficient Sustainable Urban Neighbourhood) project, which aimed to promote the energy modernization of condominiums. During this process, they prepared the project’s professional studies, namely, the situation analysis based on the survey of nearly 2000 Hungarian and Croatian condominiums, the assessment of the willingness to cooperate and the common methodology of energy modernization, along with participating in the presentation of the results of EE SUN. The project also included pilot projects for 12 South-Transdanubian condominiums, with their energy audits, full energy surveys, taking into account legal, financial and technical solutions and proposals of energy renovation for individual buildings.