I bought a cherokee while a student (and after solo) which was hangared
someplace other than where I was taking lessons (10 min flight). The
CFI drove over to my hangar for the first few lessons until he and
I were both comfortable with the cherokee. Once
the CFI had solo'd me in the cherokee, there was no problem flying over
to the other airport to pick him up.

It may be a school policy. Either way, ask him to show you the
regs or policy in the FARs.