In the domain of relationship marketing, there is an increasing need for greater understanding of ‘value’ in the process of social exchange interactions. We present a framework for analysis of value creation through these interactions. Two types of value creating interaction are identified, asset specific investment and technical exchange. Taking a series of 197 project-based, non-equity alliances between architects and building contractors, we examine value creation through these interactions. The findings establish that value in the relationship process is co-created and that this occurs through an iterative investment in specific assets at the operational level throughout the alliance. Additionally, the exchange of technical information at the operational level is found to be a source of value for the relationship and has iterative and co-creational characteristics similar to investment in specific assets. We provide an explanation for the relationship between these interaction types and relational value. We also find that goodwill trust's positive relationship with the asset specific investment interaction type is stronger in low, rather than high, operational compatibility partnerships. The implications for researchers and managers are explored and study limitations acknowledged