A great, real life example of this happened in Alexandria, VA either last year or 2021. There was an empty lot in a row of a rowhomes where another home used to be. The lot owners had to file with the city for a zoning adjustment (and have public hearings about it and everything) just to be able to rebuild the townhome that was once there.

Parking requirements, setback requirements, minimum lot sizes, and other dumb regulations make many old buildings illegal today. Have you ever wondered why modern apartment buildings all have hallways to the doors but in old ones they were closer to the staircase? That’s because modern building codes require access to multiple stairwells (but that requirement does not improve fire safety in reality).