Caroline:

Good morning. I'd agree with Bill.

Per the definitions in section 3.2 of 90.1, a cooled space (and heated
space for your climate zone in particular) is defined as a space that
contains a cooling (heating) system with a sensible output exceeding 5
btu/sf. Since you have no heating or cooling systems, I would classify
your space as unconditioned. If it is unconditioned, the comment
regarding table G3.1.1(b) doesn't apply since it specifically mentions
conditioned spaces.

Andy Phelps, PE