The foundation of your house is important to making sure it continues to stand. The foundation of a skyscraper is even more important. Years ago, I read that the challenge for making buildings taller and taller was not adding floors on top – the challenge is adding to the base. Three examples:
• Wilshire Grand Center, Los Angeles: 1,100 ft. height with five basement floors and 90 ft. supports. It also has a 18-foot-thick concrete mat that set a world record for the largest concrete pour in history.
• Willis Tower, Chicago: 1,451 ft. height with three basement floors and 100 ft. supports/5 ft. mat
• One World Trade Center, NYC: 1,776 ft. height with five basement floors and 150 ft. supports. The supports had to be built around exiting subway tunnels and extend 80 ft into the bedrock. https://www.groundworks.com/resources/how-far-underground-are-skyscraper-foundations/