Our main sink is against an outer wall, and the prep sink is in the island. We went with larger than normal space between the base cab's against the wall and the island...at least 5 feet, partially because we had the space (great room), and partially because we wanted 2 people to be able to be at both sinks preparing dinner or washing dishes and not be bumping butts.

So for us, directly opposite, 5 feet apart.

Our sinks are on opposite sides of our kitchen (16' across.) They are placed so that water is easily accessible from all areas.

Sink #1: large sink near range and near prep area. During prepping/cooking: Used for getting cooking/prepping water and dumping/draining cooking water and for rinsing hands/utensils. During clean up: used for washing pots, pans, bulky items.

Sink #2: small sink in main walkway through kitchen, on opposite side of peninsula from cooking area (and large sink), near dw, fridge, baking center, and table. During food prep: used for rinsing/peeling veggies, draining colanders and for baking. During clean up: dishes are cleared from table to this sink where they are rinsed/scraped for dw. All day long use: drinking water and hand washing.

Getting a second sink was one of the big things we looked forward to with the kitchen reno since sharing our one sink was a problem in the old kitchen during prep and clean up. Having the sinks as far apart as possible makes sharing the kitchen easier. The main sink is in the more private cooking area behind the peninsula and the prep sink is in the public area and is used all day long.

We haven't lived with ours yet, but our plan is to have the sinks fairly far away - main sink is the cleanup area, at the far end of the kitchen and next to the dishwasher. Prep sink is in the island, pretty much at the far end of the kitchen (maybe 10 feet away?) and in the prep area, near the fridge and pantry.

The point in having 2 sinks is having separate zones so that people aren't crossing paths and running into each other or standing on top of one another...and, also, so you're not trying to wash food over dirty dishes. We positioned our prep sink so it is multipurpose. It's actually on the corner of the island so it can be reached and used from 2 sides. The purposes in our kitchen:

-hand washing when coming into the kitchen

-washing prep items for the rangetop

-washing prep items from the fridge for salads, etc. done on the island

-washing hands from baking projects at the island or mixing counter

-draining pots from the stove or things cooked in the microwave

-adding water to things cooked in the micro, cooked on the stove, when making smoothies, when mixing baked goods, when making coffee or rinsing the pot (coffee pot kept on counter under the microwave cabinet)

-filling water pitchers (making juice) for meals

Maybe you won't often want to have the dishwasher open while someone is trying to use the sink...But maybe you will and why create an unnecessary limitation? In our kitchen, it happens often that I want the dishwasher cleared for table setting, or loaded from dishes used during making dinner while other cooking and prepping activities happen. If you don't want more than one person able to work at once, it seems unnecessary to me to have the 2 sinks...It isn't necessary or preferable for everyone to have a 2nd sink.

Best wishes on getting your best plan figured out!

Here is our layout so you can see sink location/separation and how someone in different zones might access each one:

Ours are roughly eight feet apart. The main clean-up sink is on the perimeter and the prep sink is on the far end of the island, just across from the stove. It's convenient for prepping veggies, draining pasta, etc. It's also accessible from the table and good for washing hands without getting in the cook's way. We put it near the end of the island (one small tray cabinet between the sink and the end) so that it would be accessible from two sides of the island. So far, this setup has proved to be very functional.

There used to be a few great threads on whether or not people used their prep sinks. Most of those who didn't use theirs said it was because of the location. I don't think it matters where it is in relation to the main sink as long as it's where you think you'll use it.

RedRoze, I located our main sink where your built-in stove is, and our prep sink is on the close end of the island to it, with our stove where yours is. I put the prep sink at that end because that was where I wanted it for working from island to stove (a lot of pretend-cooking waving hands in air while men framed the house around me). This way the clean-up area is concentrated on the short end of the L counter, my main cook area is on the island and the long part of the L opposite it, and a third work area is available in the corner between the two.

I agree with Cheril and RHome -- The distance between the main sink and prep sink is irrelevant. It's not like you walk back and forth between them.

-- The primary function of a prep sink is to have easy access to water at the space where you do your prep work. It's simple common sense for a cook to prep next to a sink, and if you don't have a sink in your intended prep area, you'll turn your sink area into the functional prep zone and your intended prep area won't get used...
-- The primary function of a clean-up sink is to allow easy and efficient cleanup of the dishes, pots & pans, etc. If it's located right by your prep zone, you may not need or use a separate prep sink (why would you?), but you may have occasional traffic jams.
-- Some sink, somewhere should also be available for hand-washing or a quick glass of water, but any sink will do for that function.

Ohmigosh...your posts have been really really helpful! I see your point about putting it where you get most use. Also why create an unnecessary traffic jam? And also, why get a second sink if you can't use it at the same time as using your main sink (using the dw with main sink is one major function of "using" it)? It's like a lightbulb went off in my head (or some other wittier metaphor)!!

I think it makes the most sense to put it on the far end of the island. That creates a prepping area, whereas the main sink is a cleaning area.

Thanks a million everyone!!