I came across an interesting discussion on Quora, the question was “Instead of building the world’s tallest skyscraper, why can’t we start building the world’s deepest building?”  Interesting question; there is of course the obvious lack of windows and fresh air but there is also engineering issues to be aware of:

• The effort to break through the earth’s bedrock to build to great depths is costly and time consuming
• The pressure of the outward soil would be great and there are limits to what our current technology can resist
• The time and cost to backfill the excavated hole would be high
• It would be a large investment, because unlike a skyscraper at the end of its life you can’t tear it down and rebuild, instead you are left with a large hole
• Of course there is also the issue of keeping the building dry and related waterproofing challenges

The consensus on Quora was that it is certainly possible to build down but costly and most likely undesirable by any tenant.  That being said here is a look at a 65-story subterranean building proposed for Mexico City as a way to get around that city’s building height restrictions.