Need for semi-conditioned attic in a new construction home with a semi-conditioned crawl space
I am building a new home that will have a semi-conditioned crawl space. We have poured a 2″ slab floor (over a vapor barrier) and the crawl space walls will be insulated with rigid foam (as will the perimeter rim joists/beams). Our air conditioning handler and all ductwork will be in the unvented crawl space. We will have one A/C/heating vent into the crawl space and excess pressure will be vented outside of the crawl space.
My question is this – since I will not have any ductwork in the attic and will not be using it for storage, should I:
(1). Consider a non-vented attic with rigid foam outside of the roof sheathing and open-cell spray foam between rafters? Or,
(2). Go the more traditional (and less expensive) route of venting the attic, air-sealing the ceiling tightly, and putting all my insulation directly on the ceiling between joists?
I live in Climate Zone 3 (far northeast Texas).
Thanks in advance for any help / advice!
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