If you leave a gap there's a good likelihood of water finding its way in there. I live in a 100 year old house- trust me, I know how water loves finding any and every crack and crevice. I can't speak as to the "right" way to do a stone veneered, 2x4 framed porch add-on because I've never seen it done that way. It's not how I would do it. Where I've seen structures built with framing, backer board, and veneer is usually outdoor kitchens (and they use steel studs anyhow). They can work because they're all supported on a poured slab, so even if the slab moves/settles, it's all doing it together. If I were building this, first of all I'd be ooked out by the idea of wood framing in contact with the ground and tied into the house (because removing the siding and attaching to the structure is what I would do). Then I'd also be concerned about how I'm supporting the walls and columns without them shifting or settling differentially. To be honest, I would do footers to frost depth (or deeper if it's a new construction home), and at that point I may as well use CMUs (concrete block) for the structure. And then if I was going through all THAT, I'd just jackhammer out the stoop and start from scratch so it was all one piece and I didn't have to worry about independent parts moving. But again, I'm looking at this through the lens of how I would approach this as a pro. As a homeowner job where you're accepting all your own liability- it could work, I guess. Maybe. As far as the design end of things, I always think in terms of having Thanksgiving at your house. With your existing porch Sid, Myrna, and their three kids can't all stand on the landing while you come to the door, but there's still kind of a connection between the up and down spaces. with what you have drawn, it's almost like mom and dad are in the vestibule and the kids are still outside. But that's just one person's thought; I'm sure others will disagree. Yay internet!

Looks like you have invested a lot of work into this project and it is looking great. You mentioned lack of funds, so I thought I would mention recycled brick as a possibility for a patio. I have a big pond on the south of the house and just a little one with a waterfall close to the house at the edge of our new patio on the north side. Love to sit there and watch the fish and bullfrogs. We got our rocks off the farm too. Water feature was our spring project 2010, and we only "bought" the liner and pump. DH made a sand filter for the water out of an old pail and :) you guessed it, sand. Works great. Whoops, also bought the funky looking water plant in the back of the upper section. Upper pond section is made from recycled wood frame with notch cut out for water to spill into lower section. Good luck with your project, have fun :)

My house is not finished yet. Possibly by next week. We plan to start moving some things in this weekend if the locks are on the doors. The edge pieces of the granite bumped up the cost. I think the mason said the corners were $11.00 each. He searched for the largest ones he could find. The other option was to have the mason cut the stone for corners. Then you add the labor cost so it would probably equal. The basic stone price was close to the Owens Corning price. I believe the price for the chimney and interior wall for wood stove came to $7,000. including labor which was a bit higher than our contractor expected. This was the first time the mason had used this product and he was very pleased with the results. He is working with a contractor who builds log homes and he stated he would offer this product. We are all happy with this project.

OK, I get it now. Real chimney to a woodburning fireplace in the basement. So the chimney has to stay. (I was thinking perhaps it was a water heater or furnace flue and could either be re-routed or decommissioned if newer heating unit has been installed.) Probably masonry but possibly prefab insulated chimney pipe. But the electric fireplace add-on is going to be demolished so you're reclaiming some floor space and are opening up part of that wall. So we're left we how to contend with what's left, which is exactly what you said from the get-go. I was over-thinking it. OP not in possession of the house until August so can't go poking & peeling off layers of stuff. Another couple of ideas after seeing some pictures. First one won't work for you but will toss it out as an idea that might work for someone else. After the fake fireplace is gone, frame it out wider and hang the TV there, with storage accessed from the side. Second idea is a tweak on the first one. Frame it out wider and make the whole shebang look like a cabinet. Part of the 'cabinet' would be chimney but the other half would be real storage. Put doors/ drawer fronts on all of it with only half serving a real purpose. Either stash sofa throws/ DVD's etc. there or turn it into pantry. (The pantry could open up to the kitchen side with dummy doors on the living room side.)