To promote scientific literacy in school science, students need to learn key concepts in science, along with the nature of scientific knowledge and how it is generated. Ideally, this learning mirrors authentic scientific inquiry through student engagement in three key epistemic practices: flexibility and creativity, knowledge construction, and collaboration. This paper draws on findings from a larger research study investigating the implementation of a guided-inquiry multimodal approach to teaching science. It reports on a case study of three Australian Year 9 science students investigating sustainable design strategies for houses, as a summative task. Through a post-hoc analysis, this paper explores how, and to what extent, the task supported the epistemic practices of authentic scientific inquiry. To address these questions, the author developed and applied an Authentic Inquiry Framework (AIF) to analyse the students' dialogue and interactions during this task. The findings reveal that the students applied a flexible and creative approach to addressing their inquiry questions, through their own experimental design and engagement in provisional and collaborative knowledge construction. To support their investigation, the students were also able to productively integrate disciplinary-specific tools and technologies.