"If I remember correctly, there is a 2,000 foot height limit for buildings in the U.S.
To have your spire on top, the actual building would have to be much shorter.
And I don't think any of us here on skyscraperpage want to see a shorter Chicago Spire".


postscript:
To clear things up.....I was initially responding to Zerton on the Chicago Spire thread.
He was advocating an earlier version of the Chicago Spire. The one with a spire on top.
I was just explaining to him that version was a MUCH shorter building (115 floors compared to 150 floors).

My post was moved here by a moderator.

[QUOTE=ethereal_reality;4243923If I remember correctly, there is a 2,000 foot height limit for buildings in the U.S. [/QUOTE]


I googled that to see if I could find anything about a height limit for towers (I couldn't), but based on the sound of it I don't think it's true. That just seems like a states' rights issue to me. The fed doesn't usually micromanage municipal areas like that.

I think the FAA had a limit on TV or radio towers at 2,000 feet, but I'd imagine that just applies to rural areas where there are likely to be low planes flying overhead and low visibility due to the thinness of the object, and again, that is just listed as reference to radio towers. Wikipedia calls it a "rebuttable presumption" which means I think even the slightest bit of political pressure would mean an exception would be made.

the FAA has legal clearance over all US territories to set height limits. the 2000ft. limit was enacted when airplanes became a major mode of transportation, and used to separate the use of high altitudes between planes and buildings(lobbying by the airline industry, before you could have built as high as you wanted). the conception of air rights are a result of this. the whole point was to prevent airplanes from crashing into buildings, planes cant cruise below 2000ft unless there taking off or landing. though that failed on sept 11th. and the world trade center collapse. the idea of the FAA allowing taller structures over the height limit is laughable, if anything im surprised they didn't lower the height limit. if any building challenges the height limit not only will they have to contend with an FAA that will not, under any circumstances gonna give an exception due to ample land area, the public outcry will be enough to kill the project before its even starts the entitlement process.

as long as there's fear of another plane crash, the height limit stays and there is no way to get around it. not even obama can change this.

So because of 9/11 we can't build anymore tall buildings. I don't see many people agreeing with you on that.

I'm not sure what world you live in, but this is America where money changes EVERYTHING and I guarantee you any FAA ruling is no exception to that fact. The right guy with the right sized wallet could get that changed in a heart beat.

Not to mention that while 9-11 had an effect on America no doubt it certainly hasn't stopped us from building taller. Couple that with the fact that airplanes, particularly air liners fly much higher then 2000ft I don't see 2000ft as any significant barrier, but more as an arbitrary number.

where is the need for 2,000 ft. tall buildings? buildings that exceed 2,000 feet are bordering on the ridiculous side and are merely for showboating (dubai) purposes. are there any business districts/downtowns in the US that are that so pressed for land that a 2,000 footer makes the most sense?

developers in philly are proposing a 1500 footer which is pretty cool and the height is definitely to make a statement, but the building will still have empty lots nearby. see my point?

when our urban areas become so maxed out that building over 2,000 ft. becomes more out of necessity rather than statement making, then i think we have an issue. but until that happens, so what?

the tallest buildings in the world now are in taiwan, kuala lampur, and dubai where those buildings dwarf the rest of their respective skylines and look completely stupid and out of place. skylines in tokyo, chicago, nyc, hong kong, and shanghai look great without disproportinately tall buildings.

^^^ have you been to Chicago? I think you are vastly underestimating the economies of agglomeration. The closer together people can pack themselves, the more efficiant it is (less energy use, more communication and idea sharing, etc) which is why you continue to see 1000-2000 ft buildings proposed and built in Chicago. There is just so much demand to live in the central area that private industry (unlike dubai) responds to it and builds tall ass buildings.


Anyhow, this rule is virtually a myth, this comes up every 3 months or so and I've made it a point to shoot it down, I found the actual wording in this FCC regulation once and it only says something along the lines of "no structure greater than 2000ft shall be permitted unless deemed in the public interest". Meaning "I am an extremely vague rule that doesn't really mean anything"... The only reason I imagine they limited the spire to 2000 feet was that it was about as high as they wanted to build (maybe Calatrava would have preferred 2050' or 2100') but they limited it to 2000' because they didn't feel like being the people to figure out exactly how to prove your building is "in the public interest"...

Here is what I had found before, it is now a source on wikipedia:

http://www.fcc.gov/Bureaus/Mass_Medi...ion/65-455.pdf

Important Paragraph:

There you have it, straight from the mouth of the FCC, NO BAN... Restrictions yes, but NO BAN...

It is also important to note that this document also says that Congress had previously considered a law that would have prohibited structures taller than 1000', but that it had not passed. It also says that they were now considering this 2000' law, which I imagine failed. Also, this rule seems to only reference antenna towers which may even suggest that it doesn't apply to actual buildings at all, I'm going to look up the statutes they reference and take a look...


Edit: I can't find anything about any of those resolutions or statutes anywhere on the internet which would suggest that they never passed and are all buried somewhere in the national archives as a mere side note to the one or two days of congressional history that they were actually on the table...

So unless someone can find something I can't, I think we have found the answer to this little myth: IT IS A MYTH! There is some truth to it (as with all myths), that they would have to apply and maybe jump through a few bureaucratic hoops, but THERE IS NO 2000 FOOT HEIGHT RESTRICTION IN THE USA...

What is the FAA height limit on mountains?

but keep in mind, it is often impossible getting around the FAA, it can be done, but very rare.

Seattle's Bank of America building is a great example, where the FAA forced them to stay below 1000feet because they felt it was too tall for the airlines through that area.

I think it is safe to say we will probably never see a 2000ft building or a building that wishes to go above 2000ft in this country....Chicago would be my only guess if that ever does happen...I dont even think we will ever see anything that tall in NYC.

But personally, I think really tall buildings are overrated.

This is from the FAA (https://oeaaa.faa.gov/oeaaa/external/portal.jsp ).


CFR Title 14 Part 77.13 states that any person/organization who intends to sponsor any of the following construction or alterations must notify the Administrator of the FAA:

any construction or alteration exceeding 200 ft above ground level
any construction or alteration:
within 20,000 ft of a public use or military airport which exceeds a 100:1 surface from any point on the runway of each airport with at least one runway more than 3,200 ft
within 10,000 ft of a public use or military airport which exceeds a 50:1 surface from any point on the runway of each airport with its longest runway no more than 3,200 ft
within 5,000 ft of a public use heliport which exceeds a 25:1 surface
any highway, railroad or other traverse way whose prescribed adjusted height would exceed the above noted standards
when requested by the FAA
any construction or alteration located on a public use airport or heliport regardless of height or location.

The relevant regulation is 2004 CFR 14 Sec. 77.23, Standards for determining obstructions. The link is: http://edocket.access.gpo.gov/cfr_20...14cfr77.23.pdf . The following FAA order about objects affecting the navigable airspace is also useful: http://www.faa.gov/airports_airtraff...R/air0501.html . Figure 5-2-1 notes that a developer has to provide the FAA notice of proposed alteration or construction if the building or tower is more than 200 feet above ground level. The height of the ground level isn't at issue. Thus, if a developer built a 175 foot building on a mountain at 5,000feet above sea level, the developer not not be required to contact FAA.

Potential obstruction of the navigable airspace has been an issue in San Diego ( http://www.signonsandiego.com/uniont...n5tootall.html), Arlington, VA (http://www.washingtonpost.com/wp-dyn...122702154.html ). and Miami ( http://www.redorbit.com/news/busines...flight_safety/ ).

Count me in the group that disagrees.

The FAA presumption against construction of structures over a certain height is set forth in the FAA rules. A proposed structure or an alteration to an existing structure that exceeds 2,000 feet in height above the ground will be presumed to be a hazard to air navigation and to result in an inefficient utilization of airspace and the applicant has the burden of overcoming that presumption. Each notice submitted under the FAA rules proposing a structure in excess of 2,000 feet above ground must contain a detailed showing, directed to meeting this burden. Only in exceptional cases, where the FAA concludes that a clear and compelling showing has been made that it would not result in an inefficient utilization of the airspace and would not result in a hazard to air navigation, will a determination of no hazard be issued. See 14 CFR § 77.17(c).

Is it just me, or are people who post in caps more annoying than mimes?

WHY the FAA set building height restrictions....
 

Mount McKinley would have been higher, but the FAA capped its height at 20,320 feet.

i didnt say we cant build tall buildings. all i said was that building over 2000ft. are not going to be built in the US anytime soon if at all.

i live in the world of reality not fantasy also in LA :). while i agree with you that money changes everything, there in no incentive for a developer to spend millions of dollars to challenge the legality of the FAA's limit. there is no reason to build taller than 2000ft. in the eyes of the FAA AND THE PUBLIC please tell me what happens if the burj dubai was proposed in New York or Chicago? the phrase terrorist target would have been splattered all over the project, and killed before it reaches the approval process.

Once again companies are not going to spend billions of dollars to have the PUBLIC let alone the FAA tell them you cant build that high. apart from the very few people like us that want a tall building just to have a tall building most americans dont see the need for buildings taller than 2000ft. most people say just say instead of a 2500ft building just build 2 1250ft buildings.

^^^ If something as tall as Burj Dubai were proposed in Chicago it would be no problem. The Chicago Spire was actually met with encouragement and excitement by the residents of its already very dense neighborhood. You underestimate the culture in Chicago which has always been a "build it big" city.

^^^Not to mention that Chicago had also (fairly) recently given permission for a 2300' building; the CWTC. IIRC, the FAA did give permission for this.

i thought the 2000' mark was where the local jurisdiction ended and the FAA's began. for ex. a proposed 2,000' building in chicago would have to seek FAA clearance in addition to the city where anything shorter would have to simply be cleared by chicago only.