The European Ecodesign Directive is an effective normative framework that has been extensively proven to support the energy transition of numerous European industrial sectors. From an analytical standpoint, it provides practitioners with the EcoReport tool, a simplified life cycle spreadsheet that is aimed at guiding the development of ecodesign measures of mandatory compliance in European countries. In this regard, several studies have highlighted the limitations of the EcoReport tool when addressing emerging technologies like those tied to the hydrogen sector. These works also propose to further integrate material criticality and social metrics in order to enlarge the scope of the European Directive and foster the shift from ecodesign to sustainable-by-design product development. In this situation, building upon the principles of the EcoReport tool and recognizing the outcomes of the aforementioned critical analyses, the conceptualization of a novel sustainable-by-design framework is presented and applied to a Solid Oxide Electrolysis Cell (SOEC) stack for hydrogen production. The operationalization of the framework is conducted, for the first time in the context of sustainable design, by combining the use of the Brightway2 and lca_algebraic Python packages. Overall, the proposed approach succeeds in providing a complete sustainability perspective to the design of emerging technologies. Regarding the tangible lessons learned on the hydrogen-related case study, product concepts are proven to progressively improve the sustainability performance of the technology. It is noticeable that the enhancement of the economic competitivity is more limited than that achieved at the remaining sustainability indicators (i.e., environmental, social and material criticality metrics). In line with the outcomes of the life cycle contribution assessment, multi-criteria decision analysis ratings lead to concluding that a sustainable-by-design SOEC stack product concept should prioritize limiting its material intensity.