I am building a deck/screen porch off of the back of our house. Total length is 22''; screen porch half is 12'x12'6', deck half is 15'x9'6 (extra 3' leads to steps). Since the gabled roof of the screen porch will tie into the roof, I was advised to forego attaching the entire structure to the house via a ledger board, and instead design it as a freestanding structure by placing an additional beam/posts near the house (and using lateral bracing where needed).

In designing this beam, I decided to have its end posts stand 1' inside the side rim joists, whereas the other beams are flush with the front rim joists (one at 12', the other at 15'). In order to maintain two equal bays on the sides of both the deck and the porch, I've also added posts that are flush with the side rim joists. My aim is to render the beam closest to the house somewhat invisible. I will likely add some kind of skirting that will span the posts that are flush with the rim joists.

Does this only make sense to me?

Additional info:

piers/footings: 12' sonotube atop 22' round footing (per local code)

posts: 6x6 PT

beams: 2-2x12s, notched into posts

joists: 2x8s, 16' o.c., sitting atop posts (doubled up on porch sides

Here is a link that might be useful: porch plan