Would it be possible to make buildings that are entirely unique to a Civilization? For example, the Chinese could have a 'Fireworks Factory' that doesn't replace an existing building, but is entirely unique to the Chinese.

Yes.. but you would have to go through some hoops. Make a free tech at 0,0 on the grid (name it something appropriate to your mod) and disable it (no one can research). Then create a building and building class that require said tech.

You can now make new buildings for specific civs simply by referencing that building class. You are free to change the tech requirement to whatever you like. You can make as many of these as you like as long as each new building is attached to a dummy building within the disabled tech.

Thanks, I will try that.

you don't need a dummy tech to give building to civ. You do need a new building class though so it doesn't replace an existing building.

If you don't make a dummy tech then every civ can build the building class you are using as a base.

If you don't make a dummy tech then every civ can build the building class you are using as a base.

Couldn't you set the cost to -1 or something like that?

I tried setting the cost to a negative value and it simply doesn't register the building. Although... it might register the class.. Let me give that a try.

Edit: Well I'll be.. this worked fine. So the dummy building doesn't need to be attached to a tech it just needs a -1 cost and it will never appear. Oy.. and here I thought I was a genius for coming up with that!