I know you can order flags flown over famous buildings. So there's a strange ritual of seeing flags go up, back down, then another raised, repeat.
I know a lot of military vets will be gifted cases such as these: https://www.united-states-flag.com/displaycases.html Obviously, you can go big and get one that's certified to have flown over the Capitol, Pentagon, White House, etc.
I remember White House being an option but that was many years ago. I don't know if that has changed for the White house. It appears easy enough to try to get one from the Capitol though. I think it's unlikely that there's code about not lowering the WH flag; that seems made up.