Earlier quoted context omitted.
"Not really. There's plenty of room to build a ton more in San Francisco." "Anti-building regulations are the only meaningful reason why the housing supply is so restricted." Prove your claim. The GP is right that there is essentially no undeveloped land in SF; a huge part of the housing moratorium debate centered on the fact that there are only a half-dozen or so vacant parcels in the Mission. This is true across th…
SF city occupies approximatively the same area as Paris, with only a third of the population. Most of Paris is developed with a 37m ceiling, hardly skyscrapers. Cost of land goes up with density, but that's the point. You build more and spread that cost among more units. Up to a point, it is economical to build higher in that situation (then for skyscrapers you start to see cost per unit going up again). Look at all…
And so? Is it affordable live in Paris? No, it is not. I just looked up rents there, and a 500sf studio will run you around $1300-$1500USD a month. Given average salaries in the area, this does not compare favorably to SF. (As a matter of fact, the city of Paris has just enacted strict rent-control laws, because rents were seen as unaffordable.)
Also, be more specific: what part of SF are you talking about? If you're talking about the 1/3rd of SF that could be characterized as "city", the density is already quite high. Increasing the density of already dense areas won't meaningfully impact rents. But meanwhile, average density numbers completely ignore that the western 2/3 of SF looks like suburbs:
https://www.google.co.jp/maps/@37.7501516,-122.4626812,3a,75...
That's in the city of San Francisco. I dropped a pin randomly in the west side of the city. You can see Sutro Tower!
When we talk about density in SF, these are the areas that matter. Building slightly higher buildings in the Mission won't move the needle, even slightly.