Buildings used to be made of bricks and mortar. They could only go up to 10 stories because of the support problems. What made taller buildings possible was the production of long, narrow, lightweight steel beams. They are very strong and take up less space, and they are perfect for holding up tall buildings.
Skyscrapers have a steel skeleton that distributes the weight. Designing a skyscraper takes a lot more than the steel beams and deciding how many floors to build. Elevators are also part of the design. Skyscrapers have to be strong, safe and convenient for the occupants. The taller the building, the more it has to resist vibrations, like strong winds and earthquakes. All these things require special technology and planning. So how high can they go? That really depends on the planning and the budget. New technology and materials could also change and expand today’s limitations. The future may bring super-tall buildings that are like entire cities and that house as many as a million people.