In the framework of the REEEM project, three technology and innovation roadmaps are developed to highlight the role of innovation and technologies in the transition pathways toward a low-carbon EU society. The first roadmap was focused on energy storage applications in order to address the need for increasing the flexibility in the European electricity industry. The second roadmap was focused on renewable energy integration, which is necessary in order to meet European targets for 2050. The current report is the third and last roadmap evaluating the role and potential of different technologies in enhancing the energy efficiency of buildings. These technologies have the potential to reduce the energy demand in Europe extensively and are considered themselves even as a source of energy (through energy saving). The findings of this roadmap were consolidated in a stakeholder workshop on 19th March 2019 and the gathered inputs are incorporated in this final version of the roadmap. Part of the analysis in the roadmap is supported by a model-based assessment of the development of District Heating solutions in three European cities (Helsinki, Kaunas and Warsaw) and implication on resource use and energy prices described in a REEEM case study (D4.2). It further links to a study on the drivers of consumers’ choices on heating appliances, carried out through large surveys in three EU countries (D4.1a - The Role of Behaviour and Heterogeneity for the Adoption of Technologies). It finally provides insights on how innovation in energy efficiency measures and technologies may alleviate issues of energy poverty, prominent in some areas in East and South of Europe, as highlighted in another relevant REEEM study. Key indications and technology trends resulting from this report feed into the definition of the REEEM pathways, as described in REEEM D1.2b – Final Integrated Assessment Report. The roadmap is complemented by an Innovation Readiness Level (IRL) report (D2.2c), assessing and evaluate innovation readiness of technologies for improving the energy efficiency of buildings.