This paper explores an investment-centric framework for sustainable Mixed-Income Housing (MIH) developments in South Africa. Drawing from a rich dataset comprising stakeholder interviews, site observations, and document anal-ysis, the study distills pragmatic guidelines rooted in investment theory. Key find-ings emphasize the strategic role of structured Public-Private Partnerships (PPPs), the importance of greenfield developments for design flexibility and economic feasibility, and the preference for silo-based income demarcations to maintain social cohesion while enhancing housing value. The study further underscores the necessity of asset and property management, infrastructure provision, and vocational skills training to support long-term MIH sustainability. These insights inform actionable investment guidelines aimed at harmonizing inclusive housing goals with the socio-economic realities of post-apartheid South Africa, thereby contributing to the achievement of Sustainable Development Goal 11.