I see in the IRC that it includes the phrase "and accessory structures".
In the definitions, accessory structure is defined as [red]"a structure not greater than 3000 s.f. in floor area and not over two stories in height, the use of which is customarily accessroy to and incidental to that of the dwelling(s) and which is located on the same lot."[/red]
I'm not sure a llama barn applies to "incidental to" a home, but that might depend on the local culture, etc. If riding your llama to work is the typical mode of transportation, then that might qualify it under the IRC.
If the llama barn is there simply to house llamas and to market them, then I would say not under the IRC.