The chapter explains the operating principles of the affordable rental housing business model, including the role of public subsidy to meet the gap in funding between required investor returns and revenue based on affordable rents. International approaches to public–private co-financing of affordable housing are showcased, together with an interpretation of potential lessons for Australia. The chapter has been revised to include recent policy developments in enabling institutional investment, especially the Housing Australia Future Fund for social and affordable housing and state-led initiatives. The potential for large-scale private finance to underpin social and affordable housing supply is reassessed in the light of these policy developments, regulatory factors, current investment conditions and international trends in housing co-financing.