The development of energy efficient buildings has been identified as a crucial part of the challenge to reach climate targets. Energy performance requirements are one of the most concrete and actionable parts of the sustainability program of urban development processes. However, after construction, there is often a lack of evaluation and follow-up of the energy performance requirements for the buildings, which limits the understanding of the state and progress of sustainable urban development processes and the ability to capture lessons learned related to energy performance. The aim of this paper is to provide insight into how the actual energy performance of buildings relates to the development process of an urban district that has been developed with a high sustainability profile. The urban district of Kvillebäcken (Gothenburg, Sweden) is used as a case study. The results of this paper contribute to a better understanding of the efficiency of the energy performance requirement as a tool during the urban development process, taking the actual energy performance of the buildings as a starting point.