X-SEED 4000: World’s tallest tower will house 1 million people

by , 08/20/07

XSeed 4000 Tallest building in the world, Tallest skyscraper in the world will be eco-friendly mountain of a building, Tokyo green building, Taisei Corporation

There’s a lot of debate about what the tallest tower in the world currently is. Some say the Taipei 101, at 1671 ft to the tip of it’s spire, is the world’s tallest tower, whereas we might argue that the Sears Tower, at a whopping 1731 ft (and 110 stories), still takes the prize. However, if the enormous, 13,000 ft X-Seed 4000 structure ever gets built in Tokyo – it will win the worlds-tallest-building competition hands down and leave its puny competitors in the dirt.

Looking eerily like Mt. Doom in the above rendering, the mountain-like X-Seed 4000 represents a utopian eco-vision for a self-contained high-rise city in the Tokyo harbor – powered mainly by solar energy. Aesthetically inspired by nearby Mt. Fuji, the behemoth building would measure 13,123 feet tall with a 6 square-kilometer footprint, and could accommodate five hundred thousand to one million inhabitants.

Designed by Taisei Construction Corporation as an “intelligent building,” the futuristically-named X-Seed 4000 would maintain light, temperature, and air pressure in response to changing external weather conditions.

XSeed 4000 Tallest building in the world, Tallest skyscraper in the world will be eco-friendly mountain of a building, Tokyo green building, Taisei Corporation

Unlike conventional skyscrapers, the X-Seed 4000 would be required to actively protect its occupants from considerable air pressure gradations and weather fluctuations along its massive elevation. Its design calls for the use of solar power to maintain internal environmental conditions. Some estimate that the cost to construct the X-Seed 4000 structure may be somewhere between US$300-900 billion.

We’re not saying it’s impossible, but for now, X-Seed 4000 seems like more of a utopian vision for contemporary green urban planning than a viable design solution.

+ X-SEED 4000

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  1. Leland Wong July 14, 2013 at 10:07 pm

    Several countries besides Japan have visions of doing something similiar to this.

  2. RiotMurphy December 18, 2012 at 1:32 am

    The idea of “housing” up tp one mil people on about 6 sq km’s sounds amazing. Doubt I shall live long enough to see things like that happen, but I am thankful for this oportunity to sneak a glimpse into a possible feauture. How cool ! :-)

  3. nleksan May 20, 2012 at 12:39 pm

    I think the way it is designed, strongly tapered as it gets taller, will eliminate a lot of the structural integrity issues that many seem to think will prevent its construction. While modern skyscrapers have considerable amounts of sway, they are the same width at the bottom as at the top; this is much wider at the bottom, 6 square kilometers, making an inherently stronger shape.

  4. sicsok March 28, 2012 at 5:50 pm

    I love this and not because of the size of it! The most beneficial application of the vertical gardening though the “panel” prefab housing blocks’ upgrading would be. From Dublin to Shanghai many thousands are nearing “retrofit or demolish” phase. Attaching outside FRP cage grating corridors and runing plants on cagewalls shield from wind and most precipitation, shades from sun, adds fire/emerg.access and scape elevators plus roof garden-parks.

  5. khryss March 18, 2012 at 12:12 am

    Surely an endeavor as huge and massive as this proposed Titanic skyscraper would require billions of dollars and and of course a vast pool of manpower. If ever built, this will be a modern day testament to the Biblical Tower of Babel. The key motivation for this is ” PRIDE “, the ultimate goal to surpass others. AC

  6. yeahyeah December 19, 2011 at 2:33 pm

    the photo above is not the x seed 4000, its the ultima tower ,

  7. hthomp November 30, 2011 at 3:28 pm

    they must never build it, it is a monster.
    man is the ultimate plague

  8. whocouldshebe August 23, 2011 at 3:16 pm

    This will fall! The smallest stable structure at such a height can only be a pyramid or cone!

  9. Caelyn June 1, 2011 at 10:12 am

    Thanks for the insight. It bnrigs light into the dark!

  10. Magda May 31, 2011 at 11:38 pm

    Soudns great to me BWTHDIK

  11. basim May 6, 2011 at 5:37 am

    precisely like my home!!!!!!!

  12. LACHU March 12, 2011 at 2:39 am


  13. bravoshex January 10, 2011 at 12:48 pm

    Too bad for the people who live at the top, when the power is gone, and the elevators aren’t running, they’ll need to setup camp on the stairs every now and then.

  14. Nikolai November 16, 2010 at 3:19 pm
  15. openstudios October 23, 2010 at 8:53 am

    i dont think it looks so good, its rather simple, you could build a much more efficient and better looking one

  16. aung October 21, 2010 at 2:56 pm

    It\’s good idea to built tallest tower but How residents will access to reach the exist from this tower in the daily basic and other emergency situation…

  17. VINI February 7, 2010 at 10:20 am


  18. AndyW August 11, 2009 at 1:45 pm

    Sorry, I didn’t read all the comments but just to clarify about this building project, it was a design that was never intended to be built.

    Buildings & Data said: “The purpose of the plan was to earn some recognition for the firm, and it worked”


  19. fangod May 28, 2009 at 1:10 pm

    is a good idea but why build such on an earthquake table like japan why not build it underground.

  20. dakotamundi April 9, 2009 at 2:50 am

    Wow, 100+ comments and no one has noted that Mount Fuji has a tendancy to have snow on top! After summiting Mt Rainier I really cant imagine wanting to be up on top with ice collecting and winds gusting over 50 miles an hour EVERY DAY! I also wonder how much sway would have to be allowed for in a structure like this. If the tallest buildings NOW are moving up to 4 feet, this one would have to give at least 12 feet!

  21. bobeve February 9, 2009 at 11:43 am


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