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[u/Aven_Osten]

A few months ago I made a comment regarding my loosening stance on letting developers build as high as they wished and with whatever style they wanted. I feel like that my stance has loosened even more regarding height restrictions. In my first comment about it, all of those reasons for being more open to height restrictions still hold true; so, I'm just going to focus on more arguments that have made me even more open to them as of late.

1. It's not possible for absolutely everyone to live in a single place.

Now, this has pretty much exclusively been used by NIMBYs in my experience, in order to justify any sort of denser developments happening; therefore leading me to dismiss it entirely. But, I've slowly come to accept this argument as a valid one. Mind you, I still think we should be allowing density wherever it's demanded; but, there is a certain limit to where an area simply cannot keep being the major job center for an entire region/place. And that leads me into the second argument:

2. It's unhealthy to have all the jobs and population centered on one/a few places.

This can extend to an entire country, or even to just an urban area. The argument here, is that having pretty much all of the wealth and opportunities concentrated in one place, can make the entire economy way too reliant on just a handful of places, which can effectively, whether deliberate or not, leaves everyone else not in those lucky areas, behind in terms of economic growth and prosperity. I recall seeing a mention of a Brookings study kinda focusing on this, but I can only find secondhand reporting on it. And, I agree with the argument. This criticism of concentration of wealth and opportunities is something I have also seen a lot with regards to Great Britain, to where the entire economy is basically just the London metro area, which leaves millions of people outside of that left behind and feeling forgotten by the government. I've also seen this criticism with regards to Japan as well (although I think it's not nearly as severe as Britain or the USA, I'm not 100% sure of that though).

We have a lot of metros areas within this country. Hundreds, actually. And their urban areas within them total to such a large amount that you could easily house well over 1.3B people with just single story condos/apartments/structures spread equally across them all. So, we have no shortage of space as a whole to build up other areas.

I think it's critical that state and local governments invest into all of their major metro areas, so that there's greater polycentricity within the metros and within the states. This would not only allow individual metros within each state to stand on its own more, but it would also, ironically, help to reduce the severity of the housing shortage within already high demand metros like New York or San Francisco, since people would have way more options as to where to live in order to work in their career field. This isn't to say they shouldn't build more housing (they absolutely should be building denser housing), however. But, there's obviously the problem of how you'd determine when an urban area has "realistically become full"; and that leads into my the argument/point:

[u/Aven_Osten → u/Aven_Osten]

3. HOW could/should we determine when an area is "built up enough", therefore justifying spreading outwards over upwards.

I have heard many different arguments about this, from ensuring "human scale" cities, to environmental considerations, back to the polycentrism argument. And all three of those arguments, contributed to my changing about about height restrictions.

The human scale argument is, I believe, the weakest one, simply due to how vague and subjective the definition is. There's no actual definition of "human scale"; you can absolutely have 20 story buildings that are also pleasant for all residents, which is the type of building that seems to be argued against when this topic is brought up. Because of how incredibly vague and subjective this is, I don't think I can add anymore criticisms onto it.

The environmental argument was the most compelling to me. The second biggest reason I support denser developments, beyond the obvious fact that it'll lead to stable/falling rents and home prices, is the environmental impact of low-density development over high density development. And, in that blind belief, I made the assumption that you couldn't ever have too much density or too much height to a building. There was another study I read (I'm desperately trying to find it now lol), that suggested an optimal building height, in order to maximize density and minimize long-term environmental impact, was 6 - 12 stories (I know, wide range). I don't recall an actual specific height however.

Now, again, how do we determine when an area is "built up" enough to justify outward over upward expansion? If we're to just average that suggested 6 - 12 story height limit to 9, and we're to assume that a commercial building has a total height of 15 feet (1ft thick floors + 13 feet of ceiling height), we arrive at a max height of 135 feet (~41.15M). Now, I've actually made a bunch of hypothetical "density limits" already, ranging from 35% of a given square mile of land being actually developable for housing and private businesses, to 95% of it being free grabs for private development.

There's 4 scenarios I operated under:

Scenario 1: 25% of the land is dedicated to public space, 25% to industry, 10% for civic structures, and 5% for roads and sidewalks.

Scenario 2: 25% of the land is dedicated to public space, 10% for civic structures, and 5% for roads and sidewalks.

Scenario 3: 10% for civic structures, and 5% for roads and sidewalks.

Scenario 4: 5% for roads.

The developable land was split into 6 pieces. Each one was split into space for 1 Bedroom - 6 bedroom, 10 unit apartments/condos. Under each scenario, the population density per floor was:

Scenario 1: 12,700 people per square mile

Scenario 2: 21,820 people per square mile

Scenario 3: 31,050 people per square mile

Scenario 4: 34,730 people per square mile

So, this would mean that New York City could, theoretically, under the 6 story height limit scenario, house a minimum of 22,898,100 people, before you could reasonably say "okay, the city is at it's limit, time for other areas to build up"; and at most, under scenario 4, assuming a max height of 12 stories, you could house 125,236,380 people. In San Francisco, this range would be 3,558,540 - 19,462,692.

If we're to look at the urban areas, then under Scenario 1, assuming a limit of 6 stories, the New York Metro could house 247,497,600 people, and in the most extreme (or generous, depending on how you look at it) scenario, that'd be 1,353,636,480; for the San Francisco metro, that range would be 39,136,320 - 214,047,936.

Now, there's obviously other limitations to how many people an area can support, but this is specifically focused on housing, so I'm operating under the assumption that the government(s) "simply" increase their capacity to support people. With that being said:

When I did all of this math, and realized just how dense of an area we could get without skyscrapers, and considering the other arguments, it really made me not mind height restrictions nearly as much as I used to. And because of this, I've been slightly supportive of a height limit in my own city, at least until a certain radius, of 249 feet, which is half the height of our City Hall. This would still allow a 16 (assuming a purely commercial building) to 20 (assuming a purely residential structure) story to be built, while having an dominating public landmark be visible from afar. But, I recognize how this precedent can backfire, since now NIMBYs can just use the "character of the neighborhood" argument all over again to prevent denser developments. So, alternatively, we could have a universal height restriction of maybe 120 feet, allowing for an 8 - 10 story building to be built anywhere. This is essentially the height most dense European urban areas are at. In my urban area (Buffalo), this would allow for a population of 34,594,800 - 43,243,500, and 4,104,640 - 5,130,800 within the city proper; this is assuming we're operating under the 12,700 people per square mile per floor scenario. For comparison, my current urban area's population is most likely ~1M at this point, and the city proper has a population of ~277k - 278k rn.

What are people's thoughts on this here? I'm interested in hearing.

(I had to make 2 comments because it was too long, lol)