We know how to safe six-story buildings in SF are a solved prblem, and developers have no problem following building codes when zoning allows them to build 6 stories.
The problem is that most of the inhabitable stuff in SF is being rented out at >$2500 per studio in those old Victorian homes, and it's not exactly easy to just evict everyone for a few years to build higher density housing. A lot of stuff is also under rent control, and since no new buildings are under RC (and all the new construction I've seen is explicitly luxury), tearing old things down to build means tearing down "affordable" (relatively) housing to build luxury junk.
It'd sure be nice to be able to clear a few blocks at a time and start over with fresh buildings, but it's more a matter of changing wheels on a bus while it's full of people driving down the street.
It'd sure be nice to be able to clear a few blocks at a time and start over with fresh buildings, but it's more a matter of changing wheels on a bus while it's full of people driving down the street.