O.K. I don't really think it looks built-in unless the cabinets go completely wall to wall, so the 1'-5" wall would need to be full depth to the cabinets or deeper. But does that really matter ? If you want to get rid of the 1'-5" wall anyway, it won't look built in. Also a under counter frig will be 24' d. so that won't fit in a 16" deep cabinet.
What if you shortened it & didn't have it against either wall & make it look more like a piece of furniture ?
I like your plan by the way.... Good Luck

Here is a link that might be useful: granite countertops

Shelly, no, it really doesn't have to be set between walls to look built in. A couple of things that would further the look would be to have the upper and lower parts connected by a single end panel, such as one sees for instance on one-piece hutch and sideboard units. A second device is to give it the same finish as the walls or the trim in the room, rather than setting it off as different from the house it's part of by a different finish. This also works well if the cabinets have, say, a wood finish because it no longer looks like part of the set of cabinets.

granite-girl -- thanks for the tip on the under counter frig. I knew that, but forget... :)

Rosie, I think I understand what you're saying. Our kitchen cabinets will be dark espresso stain, so do the buffet in the same cabinets? I'm just still not sure about the end of the cabinets if they don't go wall to wall? Our trim will be painted cream... Any pictures?

Here's what I did with my 1910 dining room. There was just a niche and I had a cabinet built to fill the space. Because of the short window, up high, my buffet is taller than kitchen height. But I can still use it during dinner for excess dishes, or water pitchers. The cabinet is 21" deep and we love the storage.

I had two outlets installed on the matching countertop for buffet lamps.

I think you could do a nice 'furniture' piece with or without a wall....but it will look more 'built-in' if the wall is deeper.

Kompy -- thank you so much for that picture! Your buffet is beautiful!! I love the outlet idea too. The lamps really add to it!

The short walls just might be structural. It may have made the difference in span for a steel beam vs. a wood beam. Ask the designer. Deleting them makes the span almost 3' wider, which is quite a jump load-bearing-wise.
I see the small walls as an opportunity for some nice detailed trimwork.
Casey

I think I am leaning toward some sort of wall on each side of the buffet... love Kompy's picture.

If anyone else has pictures, please post! :)

I couldn't tell from your post if you were doing upper and lower cabinets or just lowers. Here's a pic of mine anyway. I tried to make my buffet look more like a piece of furniture. I needed uppers for more storage since we use this piece as our pantry. I put feet on mine to make it look like furniture.

Like teacup_princess, we put feet on ours to make it look like a piece of furniture. The horizontal area above the granite is an appliance garage where we keep the microwave and the toaster oven...the double door flips up and slides into the cabinet.

Thanks ovenbird! Yours is beautiful. I like being able to see it without a wall on one side. Thanks so much for the picture@