To me it doesn't look like there will be enough room above the door; is there a height minimum in your town? If so, maybe a landing off the door and a one step drop to the new porch and make the deck even to where the siding stops...just a thought. In other words lower the deck height.
I was planning on having a 4' x 4' landing outside of door (code) and then lowing the rest of the deck to only 20'' above the ground. This way I don't have to have a railing and the dog can jump up on the deck anywhere she pleases when we are playing fetch.