To many of you, the term "Participatory Design" is new. It means that users are involved in the design process. It is distinguished from the term "usability test". The PD process covers workshops and other situations -often in the user´s "normal" environment- were the user is asked to actively influence the outcome of the design process.
How is it related to eco friendly design? Avoiding the development of useless in terms of non-usable products is always eco-friendly: products that turn out as unsuccessful (they are either not bought or not used) are a waste of resources. To discover the user´s needs therefore needs to become part of the design process. Participatory design is the most direct method in doing so.