For the same reason(s) you need to read the other prints - and not limit yourself to the electrical.

I know, sometimes it seems we are the only trade that even tries to look at the 'big picture.' Yet, we can't afford not to.

I have a picture thread going, where I had to rework some things, because I failed to pay adequate attention to the trim details.

We've all been surprised by that under-sink point-of-use water heater as well.

The NEC itself opened a whole can of worms, when they began to require certain door hardware on the doors of electrical rooms. (I have no idea even where to get such hardware!)

Now, looking at other codes ...

The ICC 'fire code' mandates the 'path of egress' have emergency lighting. This means some expensive fixtures on the OUTSIDE of the building.

The DOE 'energy calculator' (required here by the city) plays havoc with most lighting schedules.

The City here has gone 'tree crazy.' Something to keep in mind, as you make underground runs anywhere near parking lots.

NFPA 96, which covers kitchen cooking hoods, can play all manner of havoc with the HVAC, electrical, and alarm systems ... you really need to think this one through.

"LEED," as yet a vague, undefined code, is sure to much things up. If nothing else, look for a conflict with the 'egress lighting' requirement. "LEED," as I understand it, is a fancy way of saying 'green building.'