A comment from ArchMedia on "Sharing" reminded us that we haven't discussed the whole basement conundrum yet.
It's pretty rare for a new house in Utah to not have a basement. It's considered space-banking — build an unfinished basement with the distant goal of finishing it when you need the space, when you have the money, or when you need to burn a bunch of time. We both always figured that we would do similarly and give ourselves some extra square footage for exercise equipment (which we don't own), a utility room, and storage.
We were fairly early in our search for architects, however, when the subject came up and we saw a different point of view. Unfinished basements are a gigantic energy suck. Plus, we're not sure that we would be in the house long enough to warrant finishing the basement. We are already planning separate space for a home office, in addition to three bedrooms (which ought to last us plenty long, given that we live in 1+office right now). That only left the question of storage, and we're confident that we can work in enough kitchen storage for food and dry goods, and enough outdoor storage for those bikes we ride too rarely and Tai's myriad, growing and impressive power tool collection.
Not building a basement allows us to do slab on grade, which will make our radiant heating more efficient. And it will spare me from all the scary basement creatures (cousins of the Things from the closets) who won't have space to hide in. (Fear of basements goes back to a doozy that we had in a childhood home in Pittsburgh. *Shudder*) It also gives us motivation to condense our living spaces into the ones that we'll actually use — we'll have to be more disciplined about efficient use of space if we have less of it.
That said, it's a bit disingenuous for me to argue that skipping the basement is an altruistic move because ultimately, it all comes down to the almighty dollar. And when we have fewer of them, we tend to keep better track of them. Slab on grade will cost less to pour, and we won't have the added cost of deep excavation and dirt hauling. But we'll take credit for "green," too.