Modular homes
Wrote a long ass post a while ago on cheap and basic homes that could be installed in slums, this seems pretty close to what I had in mind. Why can't this be done for Indian slums?
https://twitter.com/CatchUpFeed/status/1754430186366624086?t=FwYgsaKWKIjIBLl8a6xQ9Q&s=19