We consider recycling as a complex, non-mechanical function during the design phase. We investigate the impact of substituting pristine with recycled fibers on the main structural function of a component by applying the function-oriented spiral development approach. The integration of the function is defined and included at the requirements and the design phase. Here, the recycling-as-a-function approach aims to design by meeting the recycling criteria, while considering its impact on the global stiffness and on the efforts for typical loading conditions of a hat-stiffener with skin.