Energy is high on the agenda of the European Union and in current urban development. In this study we focus on the role of urban planning in energy efficiency in 3 Northern European cities - Turku (FI), Eskilstuna (SE) and Tartu (EE). The case studies were developed in close collaboration between the authors and representatives of the cities. The research was carried out by field trips, interviews and analysis of local reports and planning documents. This work was done in the framework of the EU-FP7 project PLEEC (Planning for energy efficient cities), GA no. 314704, www.pleecproject.eu