Background Energy consumption in EU buildings is increasing and Directive 2002/91/EC aims to develop an energy efficiency certification for all buildings. This European Energy Performance of Buildings Directive (EPBD) sets minimum energy requirements that were to be included in French national legislation by the end of 2010 and implemented by the end of 2012. Potential cost savings by 2010 were estimated at around 22% in the building sector. In addition, Directive 2006/32/EC targets end-use efficiency for energy services and management procedures in buildings such as hospitals, hotels, malls, and offices. Moreover, EU Member States were held to reduce their greenhouse gas emissions between 2008 and 2012 by 8%, compared with 1990 levels. Objectives The objective of the GREENCITY LIFE project was to implement software controlling electricity, water, and gas consumption in public buildings. Using 3D models and intelligent meters, the project aimed to monitor consumption in order to manage and audit energy in real time. It intended to make detailed data on the impact of simple measures such as turning off a computer monitor when absent available. A web platform would centralise and control all data for the municipal buildings involved in the project, something which had never previously been attempted in a project of this kind. Project actions aimed to take in all main public buildings within the target areas of Nantes in France and Vigo in Spain, involving a broad range of local stakeholders in improved integrated urban management and applications of the technology to allow users to implement timely measures for reducing energy consumption. In order to facilitate understanding for many stakeholders and comparing energy efficiency of offices or different parts of a building, energy consumption was to be expressed in euros or equivalent CO2 emissions. In addition, the LIFE project was also designed to help monitor the air quality in Dijon’s state schools to facilitate compliance with the French “Grenelle 2” legislation. Results The GREENCITY project developed a water and energy consumption monitoring methodology based on a web platform and implemented technical and awareness-raising actions for the improvement of the environmental performance of buildings. In total, the project was implemented in 53 sites (47 in Nantes and 6 in Vigo), including sports and cultural centres as well as schools. Between the beginning of November 2012 and the end of May 2013, the measures carried out by the project saved 18.4% of energy, reducing natural gas consumption by 22.6%, district heating by 7.7%, and electricity by 16.6%, helping both Nantes and Vigo meet the requirements for building energy efficiency certification. No other project has put in place a monitoring system of different energy types (natural gas, water, and electricity) of this scale in different types of buildings (schools, sports centres, cultural sites) and collected this amount of historical data for comparison. However, monitoring water consumption proved to be problematic due to technical issues in both cities, which made it impossible during the project to measure the impact of any measures taken to reduce water consumption. Even after the end of the project, energy consumption continued to be monitored in the buildings in Vigo that had been equipped during the project. In Nantes, the 20 buildings consuming the largest amounts of energy as well as all new school and sports buildings were to be equipped with sub-metering and remote-management devices, allowing to monitor the energy consumption. In order to ensure transferability, GREENCITY produced a white paper to serve as guidelines for other European cities, detailing the steps of project implementation, highlighting successes and failures, and providing recommendations for similar projects. These recommendations include a pilot phase for the hardware and software development, deploying the solution in a limited number of buildings first to validate it and only then installing it in all buildings. It is also suggested to optimise the deployment schedule through site prioritisation and clustering based on criteria such as energy consumption, type of site, occupation, and existing infrastructure. Numerous other publications and dissemination actions, including press releases, posters, newsletters, and articles, complemented the white paper. In addition, the project presented its aims and results at various conferences. GREENCITY also conducted an awareness-raising campaign targeted at other European cities, which consisted in sending project outputs and a questionnaire on the need for monitoring energy consumption in cities to contacts in 334 cities in the EU27. The analysis of the 63 replies received showed that there was a need to develop solutions since only few cities had such a tool at their disposal at the time. Moreover, the project organised the “Best performing city” competition, involving 12 schools in Nantes and three schools in Vigo with a total of 2262 students. As a result of the competition, which was intended to boost energy-saving efforts in the participating schools, Vigo managed to save 15.6% of its energy consumption, while Nantes achieved savings of 4.8%. Vigo won the competition thanks to the strong involvement of the mayor in the competition. Moreover, the energy-saving potential was greater in Vigo than in Nantes, where schools were already more energy efficient. The competition also allowed informing the general population about the project objectives and energy-saving results and hence contributed to increasing citizens’ awareness of energy-saving possibilities and daily behaviours and habits that can help decrease energy consumption. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).