The rule of thumb is 18" from counter to bottom of upper cabs and you don't include the light rail in measuring that 18" distance. The light rail is just trim in order to, well, hide the undercab lights. You should maintain your original distance of 18" from the counter to the cabinets. The light rail is just trim, and should not be included in your counter-to-cabs distance calculation. So for example, if your light rail is 2" high, your distance from counter to cabs would be 18", and your distance from counter to bottom of light rail would be 16". Also, I am assuming you will be having undercab lights. If you were to go shorter than 18", the undercab lights would be hung too low. And as Sweeby said, you want to have room for coffee maker, etc.

Thanks, everyone, for the encouragement! Exactly what I was thinking, OOTM_Mom; it's a toaster oven cubby so I likely can treat it differently than my uppers elsewhere in the kitchen. It will only be 26.5" wide so it would never do as a baking center. If I were to get rid of the toaster oven and store the KA mixer there instead, it would only be stored there, never used there. I'll have a 59" island that I'll use for baking projects. Our coffee maker is on the counter over the DW, between sink and fridge. The only other appliance we keep out is the toaster, which will stay where it currently is, on the counter by the back door; bread is stored in a drawer below it. localeater, the toaster oven vents out the sides, not out the back or top. The instructions warn that the top can get warm - it can be used as a plate warmer - but even with the upper 15" above the toaster oven, I'll still have 4.5" of clearance above it, which is more than the required side clearances, so I think it will be fine. I've checked it when it's in use and I don't feel heat emanating more than an inch or two above the oven. The bottom of the current upper never feels warm, much less hot. If I can make the cubby a little less tall, I may increase the base cab height so that the toaster oven is closer to eye level, maybe at the same height as the Advantium (48" above floor). That would give me room for either an additional drawer or taller cab storage or both below the toaster oven cubby. Perhaps something like this: [[(https://www.houzz.com/photos/mill-valley-open-kitchen-and-dining-room-contemporary-kitchen-san-francisco-phvw-vp~1860951) [Contemporary Kitchen[(https://www.houzz.com/photos/contemporary-kitchen-ideas-phbr1-bp~t_709~s_2103) by San Francisco Design-Build Firms Nerland Building & Restoration, Inc. Notice that the venting for the toaster oven is above it. I thought maybe that was because that toaster oven vents above, not to the sides, but it sure looks like my Breville toaster oven. If so, that doesn't seem like a good idea at all. The toaster oven cubby in this kitchen is definitely less than 18" high. [[(https://www.houzz.com/photos/kitchen-and-dining-traditional-kitchen-new-orleans-phvw-vp~2393877) [Traditional Kitchen[(https://www.houzz.com/photos/traditional-kitchen-ideas-phbr1-bp~t_709~s_2107) by Pensacola Architects & Building Designers Dalrymple : Sallis Architecture 'Course, I've seen enough poorly designed kitchens on houzz so I shouldn't assume that if it's done in this kitchen or others, it's okay. I will definitely double check with my KD, contractor and cab maker before moving ahead with this idea.

24"?????? Yikes. At 5'8" Id have trouble reaching into those uppers. Do you have a lot of uppers? Maybe with only one or two you might be OK storing lesser used items on the top shelves and using a stool to reach them. How streamlined are you going? I could see doing this in an uber modern, don't really cook that much, look at me type of kitchen. Oh, and 24" off the cooking surface for a range hood? That distance is too short for most usual hood specs. Typical is 30-36" or so. Which hood are you using?

I wouldn't think much about structural concerns, since the sink is small by today's standards. I'd try to put it in as small a cabinet as I felt comfortable with as it is cast iron and heavy in contrast to a stainless sink. The sink is 20 7/8" square and edged with a 1.5" over lip. It's cut out is minimum 19 3/8" square. To allow for a bit of cut clearance and simpler math, we'll use 20" as the cut out size and 21" square for the sink size. There may be sink clips that are attached under the sink that hold the sink in place. The clips are tightened by screws after the countertop is mounted - so they "count" . I didn't see Kohler say one way or the other about clips, so I'm leaving that out. What you can do as far as positioning a sink [front to back] is somewhat controlled by how the sink base is made. Speaking in generalities, there is a 1/2" to 3/4" strip of cabinet guts along all 4 edges of the top with a little extra on each side for framed cabinets as the frame quite often extends past the cabinet side. You can plan on losing 1.5" off the front and 3/4" off the back - making a total of 2.25" that isn't symmetrical [3/4" on both for framing and another 3/4" for door/drawer fronts]. It might get larger depending on your back splash thickness [some folks put 1.25" stuff back there] and your faucet. It's nice to be able to fully use your faucet handle so be sure to check the amount of clearance needed behind it for real hands to use it. To get slightly weirder, the counter top is generally at least 3/4" deeper than the cabinet with its fronts on. If the FINISHED size of the CABINET with its doors and drawer fronts on is 24" [but lots of them are some other measurement], then the finished depth of the counter top is 24 3/4". The closest the cut out can be to the front of the CABINET is 1.5" + a hair. The sink would overlap the countertop by 1.5" leaving about 3/4" exposed on the front edge of the counter. However, your countertop people might have a cow as some require a minimum of 3" of width of counter on the front. I would take their advice as they know what their materials need. So the closest the front edge of the sink could be is 3/4" to the front of the COUNTER or 1.5" if the fabricator needs 3". The back of the sink would be about 21 3/4" to 22 1/2" from the front of the counter. Remembering to subtract off another 3/4" of the remaining bit [for the back support of the cabinet & also fits most common back splash depths] means that the faucet has just 1.5" to 2.25" of mounting space. Altho you could get a faucet that squishes in there, it might be hard to use it - depends on how the handles work. It might also make the area around the faucet and sink rim hard to clean. An old timey thought might be a wall mounted faucet if you really don't want it on the side. Hope this helps.