When one of my DILs is coming home for the weekend "with a project" and after one of my DILs has been home working on a project. Otherwise, I vacuum every other week just like I do the rest of the second story and wipe the surfaces down between projects.
I do have a steadfast rule that IF I let someone visit with a house pet they have to stay in the basement. I would have to clean it daily and keep everything covered and put away if I let animals in the house.