Biggest 2 reasons is for:
* Significant added cost to make sloped roofs on commercial buildings
* Imagine the cost of making a sloped roof on something like the new Giga Factory in Texas. Also, the slope space is practically useless for something like a warehouse or factory.
* Mechanical Equipment (ACs, chillers, heaters, etc…)
* Easy installation / maintenance – with the size of most of this equipment, it would be a nightmare trying to install / service the huge AC units on commercial buildings with a sloped roof on it…
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