Purpose The purpose of this paper is to first empirically illustrate the construction of accounting for sustainable development tool (Bebbington and Gray, 2001) and, second, to discuss the operationalization of accounting for sustainable development (Bebbington and Larrinaga, 2014). Design/methodology/approach This research is based on a unique intervention-research approach, the main author having worked part-time for four years on the development of the tool for a business organization in the organic food sector. Findings This paper proposes an operationalization of sustainable development within an accounting tool and presents the results of the calculations. It also touches briefly upon the organization’s decision not to adopt the tool. The research concludes on the difficulty of operationalizing the economic, social and environmental capitals while proposing results that demonstrate “unsustainability”. Practical implications This research in operationalizing sustainable development paves the way for future potential use of the tool described, and future developments to address the model’s current shortcomings, notably in interconnecting social and economic capitals with natural capital. Social implications The non-adoption of the accounting tool raises questions about the acceptability among practitioners of visualizing the unsustainability of their own organization, in particular within “green” and “socially responsible” businesses. Moreover, it raises the question of growth and decoupling of the organization’s impact from its economic growth. Originality/value This paper makes three contributions to the current literature. First, it furthers the discussion on how to operationalize accounting for sustainable development, notably by trying to implement capital as a liability (a debt), placing its “maintenance” at the very heart of the design. Second, it offers an initial operationalization of “system thinking” within a tool to account for sustainable development. Finally, it contributes to the literature on “engagement research” through a four-year intervention-research project.