[jbay808]

I don't entirely disagree with you, but I don't think that this fully captures it. I'm not talking about a new school, I'm talking about making an existing school bigger. There's no reason that a schoolhouse has to be just two stories.

Replacing a 2-storey school building with a 4-storey school building should not require purchasing new land, so the cost of land shouldn't matter much. (The temporary school closure would be a problem, but not insurmountable - it happens). The boundaries would be unchanged. A 4 storey building might cost somewhat more than twice a 2-storey building, but that should be more than offset by the fact that in addition to the number of taxpayers having doubled, they've also gotten much wealthier over the last several decades, so there's plenty of funds available.

Each teacher would need a cost of living bonus to offset the higher price of the area, but that's equally the case in a high-price low-density neighbourhood as in a high-price high-density neighbourhood. If your 3000 taxpayers can afford to pay 100 teachers enough to live in an expensive low-density neighbourhood, then your 6000 taxpayers can afford to pay 200 teachers enough to live in that same neighbourhood when it has higher density. And if the added density reduces land values, as many complain it will, then it will only get more affordable per-teacher than it is now.