In the city building tab, there are a list of buildings that are available based on location (for example, a harbor will not appear in a landlocked tab, nor a lumber mill without a forest). 

The buildings that are not able to be built because of a lack of materials are obvious.  The buildings that are not able to be built because of the city size are more amorphous.

There are a set of buildings that I have not been able to build at all, even though I have managed to research the technology.  I have not been able to build any kind of smithy or forge to produce metal (and I yearn to equip my guys with swords and pillage my enemies); nor have I been able to build tax collectors (though I managed to build a mint).

It is hard to tell if the game is balanced or not at this stage, simply because I cannot build a number of buildings with any predictability.