Background: The transition towards a more sustainable energy system is urgent for addressing global environmental and social challenges, and will require transformative changes including improved energy efficiency in the built environment. To reach identified efficiency potentials, various policy instruments have been introduced but their effects are often unclear. In this paper, we argue that the outline of transformative policy strategies will require well-designed evaluations. The objective is to present a theory-based evaluation framework that can be used to assess existing evaluations, in order to support transformative policy strategies. The framework is also applied to provide insights from current Swedish evaluation practices. Methods: The theory-based evaluation framework presented builds on evaluation theory, policy analysis and transition research and is arranged around methods, value judgements and use of the evaluations. Moreover, key aspects from transition research are included to provide guidance for transformative efforts in the evaluations. The systematic review presented in the paper is qualitative, covering 33 policy evaluations for energy efficiency in buildings in Sweden, commissioned by Swedish governmental authorities over a decade. Results: The results of the review reveal a wide range of evaluations undertaken, using a sound methodological evaluation base that builds on a variety of methods for analysis, and application of multi-criteria analyses. Commonly, however, a rather narrow scope was applied and we note a missed opportunity for triangulation of findings. Key aspects for capturing transformative efforts, such as system-, scale-and multi-actor approaches, as well as visioning, experimentation and learning, were considered to varying extents, but could be more explicit and elaborate. Conclusion: In all, we find the proposed theory-based evaluation framework useful for assessing and discussing both robustness and transformative efforts of current policy and evaluation practices. The review of the Swedish policy evaluations further indicates sound evaluation practices, and a foundational structure for identifying and analysing transformative efforts. To fully support transformative changes, we suggest a wider system perspective and a more thorough multi-actor approach and actor involvement in the evaluations. We also stress the need to further link evaluation theory with transition research to design evaluations that can support transformative changes in society.