Have built 2:
Mud room with built in cabinets and hangers. Cannot be big enough… ever!
Tankless water on each side of house. I hate waiting for hot water.
Several drawers in lower cabinets especially corners. I did drawers both sides of oven and corners.
Larger front and back porch than you think you need.
Hanging rod built between cabinets in laundry also sink
Pocket door to hallway (can close off if kids, dogs, etc…)
Larger saferoom than you think you need
I think if I built another I would use the marble slab (think hotels) vs tile shower. Pain into keep the grout clean in large shower
Heated tile floor in baths
If your forever home then spray foam. If not the pay back is too long.
Gas stove needs to have the griddle burner in middle
Fiberglass exterior doors. Real wood is A LOT of upkeep.
Insulated garage doors (3 layer, so insulation is not exposed).
Built in shoe rack in bedroom closets.
Accommodations for hanging tvs (outlet up high)
Don’t skimp on windows!
I like brick accents inside (think entry ways/large door openings.
Office
Entry door to garage. Not just garage doors.
Everyone loves our hidden pantry. (Looks like a large cabinet)
Plenty of storage closets, entry coat closet

We chose a floor plan close to what we wanted online and then had an architect draw it on his software. Much easier to start smaller than the square footage you want. Makes for easy changes with software.