Here’s something to speculate on:
Permit for B79 (BLD2019-14528). Intertior alteration. Interior partition.
The fee amount suggests this is not a permit for the house.
Has a partition ever been built between the house and the rest of the building in the past?
Over on Nightmares, they do provide a answer to the partition. The other half of B79 was being used for storage/testing Hagrid's Motorbike Adventure, and apparently Creative isn't out of the building yet, so the permit for the partition is placed so A&D can get started on whatever house is being built there.