Assessing and demonstrating value for money to agencies funding professional learning networks is a universal challenge. The purpose of this paper is to introduce a narrative-based approach to evaluation called story-building that can be employed to complement other more traditional approaches to evaluation. Story-building goes beyond the anecdotal by constructing individual reflective stories, a collective story and a value creation story that are authentic and resonate with stakeholders because they tap into the specific and particular knowledge of practitioners. A key characteristic which sets story-building apart from other approaches is that it collects and collates both individual and collective evidence of a network's impact from different sources. Members of the New South Wales/Australian Capital Territory Promoting Excellence Network created and implemented this rigorous approach to evaluation and found story-building to be an effective practice to demonstrate the value and impact of a network.