Since the Brundtland Commission voiced its call for sustainable development, multiple actors at different levels have been increasingly interested in establishing a means to monitor performance and to assess progress towards sustainable development. Different approaches have been developed and tested, and the key role of a clear conceptual framework for guiding the assessment process has been recognized. An alternative perspective can be offered by the incorporation of a social interface analysis and a livelihoods approach in order to strengthen the evaluation of sustainable development interventions both at the project and strategic level. This paper firstly shows the link between a non‐normative approach of governance and the social interface analysis, which is explicitly introduced. Secondly, the notion of sustainable livelihoods is presented as the basis for an approach more interested in the agency of households and communities and their potential, competence, capacities, and strengths, rather than their weaknesses and needs. Thirdly, as the social interface analysis implies that theory is grounded on empirical investigation, the paper introduces a case study in four Andean communities in Central West Argentina, where inputs from the social interface analysis and livelihood research were used in order to assess the impact of an external “community‐based” development intervention. Finally, the relevance of the two approaches to foster a more nuanced evaluation of sustainable development interventions is discussed.