In workshop mode, there is a "Settlement" bar in the upper right that shows how "full" your settlement is. If the bar is full, you can't place any more objects in that settlement.
My question, then, is if we know how this is calculated. Is it by the number of objects placed, the size of objects, or some other criteria? Does placing 100 large items, like walls or staircases, count the same as placing 100 small items, like light bulbs?
Also, does scrap contribute to this max limit? I know that Sanctuary, in particular, starts off with an abundance of the yellow-outlined items you can scrap. If these contribute to the max limit of objects in the settlement, it'd be a motivation to fully clean up the settlement as a first task.