The distinction hinges on a definition. According to the Council on Tall Buildings and Urban Habitat, the needle atop the new trade center is a spire, not an antenna.

The Chicago-based council—an international organization that measures skyscrapers and arbitrates height records—defines a spire as a "vertical element that completes the architectural expression of the building and is intended as permanent." By contrast, antennas, flagpoles, and signage are considered "functional-technical equipment subject to change."

Translation: The 408-foot (124-meter) needle is part of One World Trade Center's architectural height of 1,776 feet (541 meters). The Willis (formerly Sears) Tower, America's tallest building for the past 40 years, stands a "mere" 1,451 feet (442 meters) tall.

To better understand the council and its criteria, we