Just limited by the developers for each settlement. It is unlikely that it will depend on the level of the character, and even more so on the characteristics of the computer.
PS It seems that the limit can be turned off by mods
ASDRUT
and mods can be disabled or using the console, but it all depends on the engine for some who cut down the limit with a large number of buildings, the game crashes at startup or loads for half an hour
IzmdI
Yes, not a computer of norms) I just wanted to screw up a skyscraper for myself, but here such a bummer (((
You can just download the trainer with the function of disabling the limit, and use only this function (I do it myself). The game does not crash from this method, it is checked.