They didn't move the vent at all. They built a deeper cabinet so that the vent can be seen when you look into the sink cabinet. Then 12" deep cabinets were built on the back of the sink cabinet/DW/trash cabinet. The sink cabinet is open to the wall.

Mayflowers, does your vent run to the wall vent stack near the top of the cabinets, down by the floor, midway between?

You use an island loop vent, which is code compliant everywhere. Or a Studor vent if allowed by your jurisdiction. It's not allowed everywhere.

What kind of plumber are you working with???? Actually licensed and pulling permits?

It shouldn't be this hard. Like Sophie says, do the island method.

Sophie, yes he's licensed. I am pulling the permit tomorrow, hopefully.

I did some googling today, and I think his drawing reflects what's called a "dirty arm."

Nope. Nope. Nope. Clueless. The two acceptable methods to vent your sink are illustrated above. Kick this guy to the curb. YOU should never ever apply for the permit. The permit should always be in the trade's name. If he doesn't want to pull the permit and doesn't know plumbing 101, then Buh-Bye.

We are mostly DIYing our kitchen remodel and widening a walk through, and I've pulled a permit before, so that's why I'm doing it.

Wouldn't I have to break up my concrete foundation to do the Island method? Which I really can't afford.

Top of the cabinets. I think I have some in progress photos if you think it will help, but I'd trust Sophie's advice.

You can't afford to get red tagged by this guy's work either. No way should your name be on anything that you don't personally do. You are gonna have to do whatever the Plumbing InSpector says they will approve. And that drawn above method ain't it. You dont want a sink fully of dirty water to just sit there. Or the trap to siphon dry because the connection is made below the weir.

Mayflowers, I'd love some in progress photos, if you have them.

Have you actually talked to the Code Inspector to ask what methodology your location requires for island venting? The island loop vent is approved for all jurisdictions everywhere. Venting has to occur above the trap weir.

An island loop vent is approved. A studor vent is not. I just don't think I can do an island loop vent because it requires changes below the level of the floor, which I can't do since I'm on a concrete slab with tension cables.

"Sophie, yes he's licensed. I am pulling the permit tomorrow, hopefully."

Nuh-uh. If he's licensed, he pulls the permit. I have to permit to keep my lien rights.

Joseph, I am pulling the permit because we are DIYing a remodel. Plumbing is a tiny portion of the remodel. I am hiring the "experts" when needed, but we're doing most of the work. I am not paying for my own permit for the remodel and then paying again for a plumber to pull his own separate permit.

The licensed professional performing the work is the one required to permit the work, and pass inspections. Separate plumbing, and electrical permits may be required, as well as a general remodeling permit. You need to talk to the inspector who has already inspected the rough framing, etc. He will let you know.

Everything I ever read about pulling permits has always said let the pro do it. I think you have received some good advice here.

I applied for my permit today. It covers electrical and plumbing. Thanks for the feedback, but there is no way I am paying hundreds of dollars more for a plumber to pull their own additional permit when mine covers it. It takes up to five days for the plan checker to review and respond.