I used to devolope on Roblox and how it worked was, say you have a house with over 50 parts, well to reduce loading time you could group, or have all those parts join to one part that way it will be considered one object to deal with instead of 50.
I wanted to ask if there is something in ue4 that can make a 36k object map into one object so light building won’t take so long? I experimented and I realized light building was for that 36k squares.
To merge actors you can select the actors you want to merge and the go to Window->DeveloperTools->MergeActors (you can read more here Actor Merging | Unreal Engine Documentation)
BE AWARE that light building times is not only influenced by the amount of actors in your scene but also by the complexity of them, so merging all your actors does not necesarily mean less build time. Merging actors generally have a positive impact at runtime (by reducing draw calls).
Oh ok I see, thanks for the help