Building sprawl on green fields is the default, it's legal nearly everywhere. Head out past the current exurban boundaries, and it's easy to plop down acres of

Building sprawl on green fields is the default, it's legal nearly everywhere. Head out past the current exurban boundaries, and it's easy to plop down acres of single unit housing structures. These tall buildings are illegal nearly everywhere, and most importantly, they are illegal where they make sense to build, near job centers. This difference, between what is legal and what is illegal to build, is why the alternative to these towers is sprawl. There is no other plot of land where they could be built, but people still need housing.