Pre-1920s neighborhoods in the USA are dense, yet spacious. So much of the density problems in America are due to our over-reliance on cars.
Funny thing is, people still will pay top dollar to either live in these neighborhoods, or visit them on vacation (Savanah, Charleston, New Orleans, Ashville, ...).
It's a complete tragedy, the answer is right there. Just do the same thing they did then, but today.
The problem is that building like that has been outlawed with euclidean zoning.
This is the rub, right? We can only redevelop a block or two at a time, so the only choice is for 10+ story towers. Especially because land is so expensive in these cities.
I'm curious if new residential buildings (non-luxury if that even exists) in Paris or Barcelona are only 5-6 stories high.
That's not necessarily true: it's much easier to build a duplexes/triplexes than a high-rise. Companies that can build the former cannot necessarily build the latter. IIRC when Bloomberg downzoned many "missing middle" outer-borough neighborhoods and upzoned core areas to support high-rises in NYC, many small building companies couldn't transition and just folded.
> I'm curious if new residential buildings (non-luxury if that even exists) in Paris or Barcelona are only 5-6 stories high.
I'm curious to see actual data on this, but many (most? almost all?) European cities have zoning rules that prevent building much taller than that in residential areas. It's especially true near the city center, where the restriction may apply to all buildings. So my guess would be it's still pretty common to not build high-rises in European cities -- similar to many NYC neighborhoods outside Manhattan (that weren't downzoned by Bloomberg).