So you could either send something into the Elemental Plane of Fire, or alternatively with the same conserved-resource expenditure, materialize a temporary domesticated wolf. Not, like, a barky bitey sphere or something, a domesticated wolf specifically.
The spell list is incredibly varied, gratuitously exotic, around three-quarters focused on combat (albeit this does make some sense if wizards only get more powerful by defeating monsters), and exponentially too tiny for a list of possible structures that can be made that complicated and which are key to a whole society.
But, wait, the pipes were enchanted to deliver hot water, weren't they? Maybe all the utility stuff is - magic items, right. The wizard spells are just the structures you can build using an item-scaffold, tie off, and then carry around until you fire them at something. It would make sense for those to be combat-focused, because that's the context in which you'd fire something immediately and without carefully constructing a reusable magical item to do it instead.
It still doesn't make sense how there's a short finite list of structures this exotic. Unless...
"Two wild-ass-guess hypotheses," Keltham says out loud. "Confirm or refute. Hypothesis one, only gods, or some extremely rare class of people with access to restricted stuff, can create," or rather compile but Taldane doesn't have the word, "spell designs. Hypothesis two, there's a much wider variety of magicalized devices than standard wizard spells, too many for there to exist a comprehensive book set listing them all."