2 ideas
In a hot climate, much of daily life can take place in courtyards, terraces, verandas and rooftops, which are open to the sky rather than enclosed. Correa treats these as a graded series of spaces from fully roofed, through partly shaded, to fully open, and argues they should be designed as deliberately as rooms. Because open space costs far less than enclosed space, planning for it lets a poor household get more usable living area for the same money.
Correa argues that densities of roughly 500 people per hectare, comparable to many high-rise schemes, can be reached with one- and two-storey houses arranged around shared courtyards. Each family gets its own plot and can extend the house over time as income allows, as in his Belapur housing in New Bombay. The approach rests on three principles: equity, meaning plot sizes kept within a narrow range; incrementality, meaning houses grow with their owners; and pluralism, meaning residents vary their own houses. Together these let a city of migrants house itself cheaply without towers.