(4) "school property" means:
(i) a public or private elementary, middle, or secondary school building and its improved grounds, whether leased or owned by the school;
(ii) a child care center licensed under chapter 245A during the period children are present and participating in a child care program;
(iii) the area within a school bus when that bus is being used by a school to transport one or more elementary, middle, or secondary school students to and from school-related activities, including curricular, cocurricular, noncurricular, extracurricular, and supplementary activities; and
(iv) that portion of a building or facility under the temporary, exclusive control of a public or private school, a school district, or an association of such entities where conspicuous signs are prominently posted at each entrance that give actual notice to persons of the school-related use.
It seems to me if you are talking about a multi-purpose building, if the area utilized by a school is not signed, it's open to permit holders along with the rest of the building. I'd gladly be corrected by any experts. Please chime in.
I think I have said this before, but to most decision-makers, this is a fairly subtle and esoteric portion of the law as far as they are concerned. It's tough to debate the meaning of the law when you are in handcuffs.
The absolute, solid-gold, best bet is to obtain:
written permission of the principal or other person having general control and supervision of the school or the director of a child care center
... although I admit, in most cases that is next to impossible. Choose your children's schools wisely.