This chapter examines how relational design can support sustainable business models rooted in living heritage. Using the award-winning case of Serfenta (Poland), it shows how design methodologies can transform traditional crafts into innovative, community-oriented enterprises that connect cultural continuity with economic resilience. The research employs a qualitative approach based on semi-structured interviews, focus group discussions, and secondary data analysis. Findings reveal that relational design strengthens social ties, facilitates knowledge transfer, and enhances the adaptive capacity of local communities. The results are interpreted within the concept of heritage as a system—a dynamic network of actors, values, and practices shaped by continuous interaction. Within this framework, design acts as a mediating force that links tradition with innovation, supporting both cultural sustainability and market relevance.