I think it's a bit different: property tax taxes the actual property that is located on the piece of land, i.e. single family home, for its current value. Land value tax works differently: tax authorities ask themselves a question: "what is the most profitable thing one could possibly build on that land?", and they tax you based on that. Which means that if you build a single family home in the neighborhood of 7-stories apartment buildings you will be taxed as if you owned an apartment building. And the only way for you to be able to afford those taxes is to actually build 7-stories apartment building there.

EDIT: I know I'm simplifying a bit. The actual tax laws might not be worded the way I described it, but the net effect is exactly this: you are taxed on the potential resale value of your land, which is highly dependent on "what's the most valuable thing that can be built here?" question.