I think I can answer you, In America there is something called the missing middle where there is skyscrapers and then a block later you find single family homes. Urban planners like to invest in midrises, duplexes, and other forms of housing. With gentrification, urban planners do lots of studying to projects that are big and cause displacement.

What strategies do urban planners use to increase the availability of affordable housing in urban areas?

What measures can urban planners take to prevent gentrification from displacing low-income residents?

Your insights would be incredibly helpful, thank you.