Speaking of basements, Along with 9 foot tall walls or taller, you should decide whether you find "support poles" acceptable or not, down in the basement.

One friend, built about 10 years ago, and with their design, he has one pole, right in the middle(of an open area) = He had to put foam around it, because his daughter's play area, was down there and if they got to "roughhousing" then it was a hazard. (young boys, would have been worse)

This guy's older brother, just built a house, after a fire, and he has 4 poles, in his basement. Two poles, were covered by a "dividing wall" between storage/utility room and his living area, but the living area (in basement) still has two poles. His I-beams are 9" tall, under main floor (even with the poles) and I believe he said the I-beams would need to be 18" if he had gone with "no poles" option = then the basement walls need to be taller yet, so you have headroom, after you "box in" those big I-beams, to make a living area look nice.

This is just something to not overlook, during design.