There isn’t any official definition or set height for a skyscraper. Usually a skyscraper is described as a very tall building that towers above the other buildings along a city’s skyline. Some define any building with 20 stories or more as a skyscraper, others as 50 or 100 or more stories. The word skyscraper was originally a nautical term that referred to the tall sails on a sailing ship.
Today’s image of a skyscraper in our urban society is that of a mega structure rising to the sky that can only be found in a world class city such as Hong Kong or New York.
The structural make-up is different for skyscrapers. Buildings not exceeding four floors can be supported by their walls alone; while skyscrapers, as they are taller and heavier have to be supported by a large network of steel and concrete known as a skeletal frame. The walls then hang from this skeletal frame.
Skyscrapers generally have a steel structure with a core column. The core is usually made up of reinforced concrete and the elevators and plumbing are contained within the core.
Tall buildings were first introduced in the late 1800s. As buildings reached six floors and above, a problem arose- water pressure. Normal city lines were not adequate to supply a whole building. To fix this problem, water tanks were installed on the tops of buildings taller than five floors (about 50 ft, 15m). The word ‘skyscraper’ was then assigned to these buildings over six floors.
It was also very impractical to make people walk up all those stairs. The invention of the elevator was needed.
First Skyscraper, Home Insurance Building
Debatably, the first skyscraper erected is the Home Insurance Building in Chicago, which was 10 stories, supported by steel and constructed in 1895. In fact, the building weighed 1/3 of what it would have weighed if it had been constructed from stone. In 1890, two additional floors were built on top of the original 10-story building.
People do not normally think of the ‘shorter’ buildings being ‘skyscrapers’, but really if they are over six floors, they are. You never know, there could be a skyscraper right around the corner from you!
Tallest vs. Highest
We would like to set the record straight about the following grammatical error that often comes up when talking about skyscrapers. There is a fine difference between the highest and the tallest building. Let us explain:
By definition:
Highest – “Having a relatively great elevation”
Tallest – “Having a specified height from bottom to top: a plant three feet tall.”
Here’s an example:

B is higher than A, but A is taller than B
So if someone says the Burj Khalifa (World’s tallest building as of January 2012) is the highest building in the world, they are incorrect. There are many other buildings with higher elevations around the world.