Dump the 30", make the 36" the sink base, and eliminate the seam.

What is the counter top material? Does it have movement?

Quartz, little movement

You've got 123" of cabinets and a 12" overhang, 135" total; a jumbo quartz slab is 132". Make the 30" a 24", make the 36" the sink base, and you've got no seam.

Probably not possible, but I'd seriously redesign the island plan to avoid a seam (by making it no more than 120" or going with a jumbo slab as mentioned above and designing to make the 132" work) -- Unless you have seen the counter installer's work w/quartz and seen that they can do a perfect seam (and even then), you will see it -- particularly in a relatively solid quartz -- ask me how I know? I've got a solid-ish quartz and a 13' run of cabinetry. Hate, hate the seam, and would hate it no matter where in the run they put it.

Also, based on my experience (and those kitchen designer recommendation people) I'd allow for a 15" overhang for seating -- 12" at counter height is not enough leg/knee room.

rmsaustin:

If she reduces the cabinet 6" and installs the jumbo, she gets the 15" overhang for free.

Thanks for the advice. The island is in, so no changes possible to the cabinets. Another thing we should've checked out more during the design phase.

The 36" cabinet isn't full depth, it's narrower and gives 18" overhang for seating on that side of the island. I've talked with contractor about increasing the overhang from 12" to 15" on the end. We tried it out with our stools (have plywood on island), it's doable with 12", but 15" is better. It still leaves us with a seam - either over trash pull out, or the sink. We're leaning towards the sink - we know it can be an issue if it's not done correctly. Contractor hasn't had an issue with the fabricator, and my dealings with fabricator have been encouraging (no issues with doing positive reveal or a more rounded edge profile for the sink cutout. ) I have seen their work and the seam was well done. We'll talk with them more this week.

I have 15 inch overhang and I don't think it is enough. I would definitely not go lower. Just my two cents.

Do you have pictures of the final result? I’m currently looking at a 12’ Island as well (8’ for sink dishwasher trash and 1 cabinet and then 4’ open for seating)

I could go down to 11’ if my slab (polarstone) comes in a jumbo size but that makes the seating area 3’ and a little cramped so if I can make it work at 12’ id love to but haven’t seen a picture of a seam in an island.

Thanks!
Sarah

I am a fabricator. Properly done a seam in quartz can be made VERY inconspicuous, i.e. you have to look for it to see it. Since you have overhangs I would locate the seam such that there is no seam in an overhung area assuming that's an option. Ask your fabricator to show you an island seam they've done (not just a countertop seam as long island seams are harder to get perfect) so you can see what you'll get.