[bluGill]

The design should have added time (since is was a new thing and thus who knows how long before they can design something that works - this may require building labs to simulate things in). Everything else should just be a month extra. There is more to do not, but you can put the AC in on lower floors while placing beams for upper floors. Plus we have a lot of automation that has been made before this, so a lot of labor should go faster. A taller building will of course take longer to build than a short one, but it should be years difference.

[Retric]

Where are you getting that should from? The base took a long time and was literally built like a bunker, but the actual floors went up at roughly 1 floor a week. However, there was a significant gap between all the glass on exterior being up and the building being ready for occupancy.

Part of this is tall buildings simply run into issues with workforce sizes. The same happens for developers building thousands of single family homes run into similar issues. They can build individual homes vastly faster than they can finish a large subdivision.

Elevators are also a bottleneck etc.