|CITyFiED project aims to develop a replicable, systemic and integrated strategy to adapt European cities and urban ecosystems into the smart city of the future, focusing on reducing the energy demand and GHG emissions and increasing the use of renewable energy sources by developing and implementing innovative technologies and methodologies for building renovation, smart grid and district heating networks and their interfaces with ICTs and Mobility. This strategy has the following pillars: 1.Large scale demonstrations: three holistic district renovations at Laguna-Valladolid (Spain), Soma (Turkey) and Lund (Sweden), deploying innovative and cost-effective technologies for a high increase of the overall energy efficiency and a relevant reduction of the environmental impact. A deep retrofitting of the buildings, an innovative district heating and cooling concept and a set of solutions to improve the grid management and increase the distributed electricity generation are going to be carried out in order to achieve powerful models suitable for replication across Europe. 2. Maximization of the replication potential: organization of a cluster of cities. More than 15 cities have already signed a letter expressing their interest to be part of this cluster. 3. Development of innovative and cost effective methodologies and procedures for planning, deploying and replicating energy efficient district retrofitting actions, resulting in low energy and zero emission cities and urban areas, deploying HVAC facilities based on a district scale and also integrating distributed electricity generation. 4. Dissemination: It is also foreseen to give a clear message to professionals, academic audiences and the citizens in general, about the benefits of the energy efficiency in the city environment, but also addressing complementary issues such as mobility, in order to modify the user behaviour towards a more sustainable awareness.