Today, cities allocate about 50% of world's population, and it is expected that this number will increase up to 80% in the upcoming years. The urban territory is responsible for a high percentage of natural resources consumption and waste generation, and therefore resource efficiency is critical to promote local and global sustainability.The characteristics of urban morphology and the growing trend toward urban transformation give cities enormous leverage in this respect. A Smart City could be an answer for improving energy efficiency, human living and environment, economy and governance. There already exist various initiatives proposing different framework approaches for Smart City concept, although some key fields are common in each approach. In this paper a review of some initiatives regarding Smart City approach is presented in order to have a more accurate image of this complex concept. In the second part, a recently approved research project “SusCity” project takes an integrated and application-oriented research approach by focusing on urban interventions in Lisbon city. The project approach will be explained together with the first work set up.