Integrating environmental aspects in the design process is getting more and more covered by the actual scientific research. Based on various fields such as "eco-design", "Design for sustainability", "eco-innovation", several specific software and methods have been developed to tackle this issue. Our work focuses on product designer software and eco-designer software that already exist. This research analyses product design and eco-design--considering their respective complexity--in order to determine the main difficulties to systematically integrate environmental aspects in the design process. Our observations have led us to work on three elements: information, software, and collaboration between designers and LCA expert. The principal objective is to facilitate the interface between product design and eco-design by linking the requirements and performances of both domains. It seems therefore necessary to help the collaboration between various experts and thus to develop a digital interface enabling designers to exchange data and to use their appropriate related software. The aim of this paper is to argue the need of a digital tool interfacing the actual tools of the design process and of eco-design (among the related software such as CAD, CAx, PLM, and LCA). This "digital interface" is presented at the end of the paper and will be created next year.