[ensignavenger]

Enacting sane regulation that does what it is intended to do and has no or few side effects is more difficult when you try to regulate each individual action some one could take that may have negative externalities, rather than regulating the production of the negative externalities.

Edit to add:

And by regulating local externalities at the local building level rather than the city level, you are more likely to have better regulations in regards to residents and owners wishes.