which is the highest building in the world?

Answer 1

Currently, Taipei 101 is the tallest occupied building. The CN tower is the tallest freestanding structure.

When it's completed, the Burj Dubai will be the tallest structure period.

Answer 2

The tallest standing structure is the KVLY-TV mast near Fargo, North Dakota United States, at 621 m (2,037.4 ft). It is a transmission antenna, consisting of a bare metal structure supported by guy-wires. The Warsaw radio mast at Gąbin-Konstantynów near Warsaw, Poland at 646.4 m (2,121 ft) was taller, but it collapsed on 8 August 1991.

These transmission antennas are not usually included with the world's tallest buildings because they are not self-supporting.

The Taipei 101 is currently the world's tallest highrise building at 510.39 m (1,675 ft) (previously Taipei 101 - 509.1 m (1,670 ft)) as measured to its architectural height as well as roof height 448 m (1,470 ft) and highest occupied floor 439 m (1,440 ft). The Sears Tower has the highest absolute height (to the top of antenna) of any building in the world at 527 m (1,729 ft).

The Burj Dubai, which is scheduled for completion in 2009, will break all of the above records, in all categories, for any building or structure, ever. While the final height has not been released to the public, the developers state that the building is estimated including antenna/spire ~818 m (2,684 ft) (estimate).

Answer 3

I think its the Taipei 101 tower. Before that it was the Petronas towers in Kuala Lumpur.

There are some buildings under construction that will be taller than these when they are completed.