Fully expanded first floor
Fully expanded basement
6x6 2nd floor
6x6 room on the left
That's it so far. I'm working on paying off that fully expanded basement loan. It's been going very slowly because I haven't had much time to go beetle/shark hunting lately and so far my town has only been giving me small profits for turnips. Turnips buying rates have been between 100-110 bells and then I am averaging 130 bell sell rates. At least I'm never losing anything, but at the same time, it's not making me rich.
My main room, upstairs, and left-side room are all fully expanded. The back room, basement, and right-side room are still at the initial sizes. My exterior is fully upgraded - castle design and Fairy Tale fence, mailbox, roof, pavement, and siding.
I haven't been racing too much to get everything expanded because I've also been working on PWPs and built the starter houses for my three dummy characters.