Background Appropriate housing is an urgent issue for both older adults and university students. Internationally, governments are promoting ageing in place, but rising demand for in‑home support is straining resources and increasing delays to access. At the same time, housing affordability is worsening globally, leaving university students especially vulnerable to precarious living situations. Homeshare offers a potential dual solution: a mutually beneficial arrangement that reduces social isolation for older people while providing affordable housing for students. Methods Five older adults (55+ years; 4 Female) and five university students (18-35 years; 2 Female; domestic and international) engaged in a three-round RAND/UCLA Appropriateness Method to review existing evidence and co-design an Intergenerational Homeshare Activity (I-CHAt) Framework for the Sunshine Coast, Australia. Results and Discussion Based on agreed principles of mutual benefit, fairness, flexibility, and safety, the co-designed I-CHAt Framework connects four related parties: provider, homeowner, homesharer, and home environment. The framework guides across five identified key stages of homeshare: i) promotion and recruitment, ii) developing matches, iii) homeshare agreements, iv) maintaining matches, and v) supporting matches (closing). I-CHAt is an evidence-based and pilot-ready program of intergenerational homeshare presenting a viable option which may prolong healthy life years in older adults and support the health and wellbeing of younger adult students. The community aged care sector is shrouded in uncertainty at present; I-CHAt has the potential to help delay the need for such care in older adults, providing novel alternatives for social connection and wellbeing that can be supported by innovative service providers.