That’s another good point, and yet all of that might be further confounded by historical preservation laws that might prevent demolition. It’s not unknown in San Francisco for developers to dig up and physically move some old dump to another location because they can’t get clearance for the new project without preserving the old dump in one way or another.
Historical preservation in San Francisco is an amusing concept.
Most of those old structures are one decent earthquake away from demolition anyway.
:-)