I would have criminalized “owning residences you don’t live in”.
I may misunderstand what you mean by “residencies”, but wouldn’t that include hotels, offices, shopping centers and sport centers as well?
Those are businesses. Noone is “residing” there, i.e. living there long-term.
That’s a loophole that would be abused. “Oh, this empty-looking house? It’s just a small hotel, business building! Why does it look abandoned? Oh, you know, legal stuff and stuff. I totally don’t keep it around as an extra house or anything!”