re: New Residential Construction Must-Haves/Nice to Haves

Hookups for future upgrades (whole house generator, outdoor kitchen)

My pantry is big enough for a second refrigerator and chest freezer. Wish I had run a water line in there to make ice.

Double check all door swing directions, light switch placements, a/c duct locations, bathroom vent locations.

Put exterior can lights under eves so you can do smart LEDs for holiday colors/purple & gold/Mardi Gras.

At least one hose bib at 4 corners of the house.

Ethernet behind every TV. Especially patio TV. Maybe also in garage or storage because I have smart bulbs in my outdoor flood lights that turn on/off with sunrise /sunset and they have trouble connecting sometimes. It'd be nice to add a mesh router outside for this.

ETA:
Make your garage 2' wider and deeper than whatever the plans say.