How does transferring from a current plot to a new plot work?

[Jojoya]

Well, Mao has successfully relocated to a medium. Mao is wondering if Mao needs to purchase builder's license again or is Mao now set?

You should be set. The Estate Hall is included in the relocation.

All furnishings placed in your small should have been moved into the Storeroom with the exception of the Miniature Aetheryte and Chocobo Stable if you had them. Those will be automatically be placed in the yard/garden.

Your exterior fixtures should be automatically placed on the new house, with the walls and roof upgraded from small to medium automatically.

Your interior fixtures should also be automatically placed inside the house in their respective ground floor and basement positions with a default set of fixtures placed on the upper floor you now have.