building system

i need to find a way let my game run smooth on some pc
first is my building system has some problem
my game has a large map so i need to save some performance for AI or other
i see some game like ark survival can make many build as you want
so can i ask do the game using instance static mesh or just all actor because there has some data save on the build like hp
and is it using world composition or other tip i dont know

ps : sorry for bad english