For most people, the word "skyscraper" is a relative term for a building which seems to reach the sky. In one city a 20-story building might be called a skyscraper, whereas the same building would get lost in the Shanghai or New York skylines. In order to provide consistent statistics, the editors of Emporis have agreed on a metric definition of a skyscraper: any regular multilevel building with an architectural height (ESN 19417) of at least 100 meters (328.08 feet). More details: skyscraper definition (ESN 24419)
The parameters for measuring skyscrapers are a great source of controversy, because different people are willing to accept different building features in the height. Ambiguities result from elements such as antennae, sculptures, spires, and pyramids at the tops of buildings, as well as sloping ground and elevated platforms at the base. Emporis solves this problem by collecting data in 8 different height types, each using different parameters. However, in accordance with tradition and with its reliance on architectural data, the primary statistics published on Emporis use the architectural height (ESN 19417), which counts everything belonging to the architectural design and which rises above the lowest adjoining sidewalk level. Antennae, satellite dishes, lightning rods, and other elements added on top of the architectural design are listed in the tip height (ESN 56239), but are not counted in primary statistics because (a) they can be viewed as temporary "furniture" resting on a building; and (b) data on them is rarely available except for the tallest buildings. On the other hand, while many people prefer height rankings which exclude spires and sculptural elements, there is no clean way to exclude these from buildings without losing the impact of skyline-defining elements like pyramids and screen walls. Emporis' standards differ from those of organizations like the CTBUH by including the whole man-made construction at the base, including platforms which rise above street level. More details: height types (ESN 15705)