Environmental regulations and public pressure lead more and more companies to adopt an ecodesign approach. Nevertheless, this desirable change is slowed down by some difficulties in integrating the ecodesign tools and methods in the already complex product's development process. In parallel to other initiatives which try to develop global platforms with interoperable tools or to propose management tools to drive the ecodesign integration, we believe that a knowledge centered approach is necessary to support the ecodesign processes in a perennial way. Thus, the aim of this paper is to identify situations in which lack of knowledge can affect ecodesign activities and how to overcome these difficulties. A brief literature review emphasizes the key role of knowledge in design and explains the reasons why this role is exacerbated in ecodesign. Based on empirical material and academic papers, we define some scenarios that illustrate some key knowledge issues in ecodesign, and that show how some functionalities could help to overcome these difficulties during the design process. Finally, we suggest integrating those functionalities into a collaborative platform. Focused on interactions between the ecodesign stakeholders, its main purpose would be to support knowledge construction and knowledge sharing.