I think there may be a disconnect here (and I apologize if there isn't; this is not my wheelhouse)...
1. Some people talk about "land tax" meaning a tax on the value of _only_ the land. So you pay a tax based on the land, but not anything built on it.
2. Some people talk about "land tax" meaning a tax on the value of the property if you were to sell it; including any construction on it. This is the common situation in the US, to the best of my knowledge.
The former, taxing _only_ the land, is what (I believe) a lot of people are talking about when they say it will promote more/better construction on the existing land. Because you're paying the same tax regardless of what is built on it, so build whatever it the most useful for you.
1. Some people talk about "land tax" meaning a tax on the value of _only_ the land. So you pay a tax based on the land, but not anything built on it.
2. Some people talk about "land tax" meaning a tax on the value of the property if you were to sell it; including any construction on it. This is the common situation in the US, to the best of my knowledge.
The former, taxing _only_ the land, is what (I believe) a lot of people are talking about when they say it will promote more/better construction on the existing land. Because you're paying the same tax regardless of what is built on it, so build whatever it the most useful for you.