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 follow the activities required for machining a set of features which are tool setups , fixturing setups 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.