We are building a Single story brick house in central NC.
Crawl space is to be conditioned.

We are in the process of obtaining quotes for Spray foam insulation. We are currently only planning to spray foam the underside of the Roof deck, and the attic would be unvented so it would end up a conditioned space attic.

There is no HVAC in the attic and no HVAC ducts in the attic. (these are entirely located in the crawl space)

Our primary goal is to have a temperate environment for storage in the attic.

The heated sq footage is 3500sq ft. The area of the garage is about 950sq ft. There will be no finshed rooms over the garage, only unfinished attic space.

Is there any advantage or is it necessary or advisable to spray foam the underside of the floor of the attic over the garage? We would prefer not to do this unless it is necessary since the quotes are already expensive. Is it ok for the floor of the attic over the garage to have no insulation? The attic space over the garage connects directly to the rest of the attic over the heated area of the house.

Any advice or help is appreciated!
Thanks!