This is the major factor that makes rents so insane in prewar parts of cities, where the few remaining dense old neighborhoods in city cores are targets for gentrification. People want to live there -- and demand is rising as large numbers of millenials reject the suburbs -- but there cannot be any new supply built due to zoning laws.

For example, almost all of the expensive dense old Boston inner suburb of Somerville would be illegal to build today under its present zoning laws: http://cityobservatory.org/the-illegal-city-of-somerville/

What neighborhoods are you talking about? I don't see anything near the Brutalist style anywhere in the city. A lot of the older parts of Houston have those three story townhomes, but they all look pretty nice. A lot of the homes that those places are replacing were pretty rough.