Standardisation is an essential element in various sectors to avoid conflict, duplication of effort and establish a common language between key actors. Even though Energy Efficiency (EE) is a high priority for the European Union (EU), it lacks common standardisation procedures and methods among interested parties. EE investment ideas usually lack a common framework on which projects are considered profitable and merit attention by investors, while financing institutions mainly evaluate the creditability of the company that develops the project rather than the project itself. In this framework, the present study proposes a multidimensional benchmarking approach for the identification of bankable EE project ideas. The methodology aims to set the pace for EE project developers and investors to establish a consensus based on which EE investments are bankable. Unlike other approaches, the proposed methodology establishes an integrated approach, especially in terms of variety of investors and financing options, taking into consideration all possible benefits of EE investments, providing awareness concerning their compliance with the EU Taxonomy, deploying KPIs and thresholds broadly used by EE and financing sector, and providing a hub in which these projects could be financed. The benchmarking deploys outcomes that have emerged from lessons learnt, databases of already financed projects, and stakeholders’ consultation to ensure that the evaluation is in line with market needs.