Sustainability in Higher Education: A Systematic Review and Conceptual Framework of Institutional Maturity (SHE-IMM)

This study conducts a systematic literature review (SLR) of 406 peer-reviewed studies on sustainability in higher education published between 2014 and 2025. Guided by the PRISMA 2020 framework and the PICo criteria, this review identifies thematic patterns, institutional enablers, and barriers shaping sustainability integration. Data were manually screened and thematically coded using a structured extraction template. The findings reveal a conceptually active yet uneven field, with curriculum and pedagogy dominating discourse, while leadership, policy coherence, transformative learning, and global citizenship are less examined. Barriers such as institutional inertia and fragmented policies persist, but enabling factors, including digital agility, collaborative governance, and community partnerships, are attracting attention. Resilience and climate change education remain underexplored, indicating a gap between institutional strategies and sustainability goals. This review contributes by (i) identifying critical under-researched areas, (ii) refining a keyword framework to guide future inquiry, and (iii) introducing the Sustainability in Higher Education (SHE) Institutional Maturity Matrix (SHE-IMM), a conceptual model categorising institutions into foundational, transitional, and transformative stages of sustainability integration. The review received no external funding, and the authors declare there are no competing interests.