The CITYkeys project has resulted in a set of indicators (download) for assessing the success of smart city projects, which is linked to a set of indicator for smart cities. Since the 1990s, various 'city sustainability' indices have been developed that aim to provide a ranking of cities. More recently, organisations supplying green certification schemes for buildings have moved into green certification of neighbourhoods, districts and in an extreme case, even cities.


CITYkeys aims to speed up the transition to low-carbon, resource-efficient cities by facilitating and enabling stakeholders in smart city projects and cities to learn from each other, create trust in solutions, and monitor progress by means of a common performance measurement framework. Transparent and flexible, the CITYkeys performance measurement framework can be applied to a large variety of smart city projects and adapt to the different local contexts of cities.


This report, entitled 'Recommendation for the Smart City Index' (download) explores existing city indices and certification schemes, and confronts this to the requirements of cities and city stakeholders.

  • It draws a standardization system enabling the comparibility of smart city project between European cities
  • It elaborates recommendations for a smart city index that can be aggregated to the city level, or disaggregated to the project level. For example: "x smart projects in y neighbourhoods lead to a CO2 emission reduction of z on the scale of the city”.


The smart city index is flexible enough for different kinds of projects and cities to work with (e.g. small/large, good data management system y/n, simple or advanced projects etc.), yet a minimum amount of information needs to be available in order to be able to serve its purpose.


Warning: the report is written for an audience of indicator developers in cities and (inter)national organisations.