For a designed part, if different sets of features are used for machining, the manufacturing Environmental impacts (EIs) as well as cost may vary. In this research, a new methodology based on feature technology is proposed in order to help designer till detail design phase to choose the most optimal compromise Environmental Impact/Cost in manufacturing process. Hence an Environmental impact/Cost model is presented. This model follows the activities required for machining a set of features which are tool set-ups, fixturing set-ups and machining tool paths. The paper starts by presenting features based models which are the base of the methodology proposed. Then, a state of the art about using Feature technology in reducing on one side manufacturing cost and on the other side manufacturing environmental impacts is presented. Finally an environmental impact/cost methodology for evaluating multiple feature-base machining methods is proposed.