“…Second, flipping the sustainability coin, the city's social foundation is threatened by a mix of urban processes such as housing, education, health, well-being, social services, governance, cultural heritages, safety and employment [2,3,5]. The point to be made in this review is that these listed challenges to the sustainability of future cities, here defined from indicators and measurements used by scholars like Tanguay et al [2], Chan [3], Steffen et al [4], Raworth [5], often exceed the coping capacity of individual urban developers such as private and public companies, including municipalities [6,7]. Therefore, the city's usual combination of influential stakeholders needs to tackle this complex dual problem of sustainable urban development when they enter collaborations such as PPP, particularly concerning housing development, the focus here [7][8][9].…”