Although innovation policy clearly recognises the importance of non-commercial activities, appropriate indicators to measure innovation in the household sector are still lacking. Therefore, despite its dynamic development and transformative potential, the phenomenon of peer innovation has received too little attention from both policy makers and researchers. The conference paper outlines the concept of peer innovation, proposes an approach to measuring peer innovation to fill the research gap, and reflects on what these considerations mean for the possibilities of conceptualising peer innovation through the framework of technological innovation systems.