You didn't specify the brand and model of the 36" induction rangetop. But the Bertazzoni MAST365IRTXT is $3900 and the Fulgor Milano F6IRT365S1 is $4250. Assuming the rangetop you're purchasing is in the same price range, perhaps you could buy the Frigidaire Professional FPIC3677RF at $2150 and use the $1800+ savings to replace the countertop and add a filler to the front of the cabinet where the old rangetop's control panel was. IMO the result would look a lot better than trying to fit new rangetop into a cutout that's too big on all sides.

I would not purchase the smaller size until there is a definite solution for the gaps.

What you have is a rangetop, not a cooktop. Changing from a cooktop to a rangetop to a cooktop of the same size is not that difficult. Changing from a large rangetop to a small cooktop is quite difficult and expensive. You need a good local custom cabinet maker to alter the cabinetry portion and not have it look like it was butchered by a 3rd grader with no skills at gluing popsicle sticks. Plus you will need a local custom metal worker to create a metal "counter" to drop the new cooktop into if you do not want to replace all of your counters.

@Lomo: "You have to rebuild the cabinet to go from a range top to a cooktop"

Why is it necessary to "rebuild the cabinet" instead of replacing the old rangetop control panel with a piece of wood and painting it to match the rest of the cabinet?

@DeWayne: "Changing from a large rangetop to a small cooktop is quite difficult and expensive. You need a good local custom cabinet maker..."

Why can't she just add a filler panel where the rangetop control panel was and replace the countertop? Why is this "quite difficult and expensive"? Why does it require a "good local custom cabinet maker" to cut a piece of wood the proper size, attach it to the cabinet, and paint it?

In speaking to the cabinet issue, you have the option to get a functional upgrade. You can remove the 42" base cab and replace it with a 42" 3 drawer unit. You'd get valuable pot and pan storage with the top drawer giving you utensil storage within the installation requirements of your cooktop. Miele requires a small amount of clearance for ventilation of the electronics, for example.

Or, at a minimum, the cabinet maker can make a functional top drawer there instead of a nailed shut ugly piece of wood finished in a house paint that doesn't even match the cabinets.

@DeWayne: "the cabinet maker can make a functional top drawer there"

"It is not recommended to use drawer underneath cooktop. Empty space is needed for installation purpose." -- Installation Instructions

"finished in a house paint that doesn't even match the cabinets"

How do you know that paint appropriate for cabinets wouldn't be used and that it wouldn't match the cabinets?

Way to cherry pick a model that needs extraordinary clearance. Most induction models will allow for the use of a shallow drawer under the cooktop. Especially if it's a ventilated drawer, which is a possibility that a custom maker can create. No handyman person is going to have the skills needed to match what is there.

I'd just have a metal shop fab some stainless filler panels for the rangetop spaces (sides, back) and be done with it.

Going with a cooktop creates so many more issues.

@just_janni: "I'd just have a metal shop fab some stainless filler panels"

Nope, the rangetop has to supported on all sides. One can't just stick pieces of stainless steel into the gaps and expect them to support the appliance. The Fulgor Milano F6IRT365S1, for example, weighs 65 lbs.

@DeWayne: "Way to cherry pick a model that needs extraordinary clearance."

It wasn't cherry picked. It was selected because it has control knobs like the old rangetop.

"Most induction models will allow for the use of a shallow drawer under the cooktop."

The Bosch induction cooktop requires a minimum of 3-3/4" between the underside of the countertop and the top of any under-cooktop drawer. In addition, air must be allowed to circulate from under the cabinet, behind the cabinet, and into the space between the cooktop and drawer. Based on the rangetop photo, there's not even enough vertical space for a drawer.

IMO we wait for the OP to answer questions since I think without any idea of the brand she is getting how do we know what needs to be done.

I have no suggestions for the cabinetry - but I believe this firm fabricates custom metal trim and might be able to offer suggestions since making adaptations work is their business. Good luck!

https://microtrim.com/gallery/

@L.D. Johnson: "I believe this firm fabricates custom metal trim..."

"Note: Cooktop Trim Kits are cosmetic products only and are not designed to support the weight of the cooktop." -- Microtrim

FYI...when I replaced my radiant electric cooktop with an induction cooktop, I had to remove the top drawer since the drawer did not allow proper ventilation. In my case, we just removed the drawer front from the drawer box and attached it to the cabinet. You cannot tell it's not an actual drawer. I do miss that drawer!

We put in a Café cooktop.

It was not my intent to suggest the trim would support the weight of the cooktop. My thought was Microtrim might be able to suggest some combination of trim plus underlying support structure.

@Buehl: "we just removed the drawer front from the drawer box and attached it to the cabinet"

As shown in the photo above, a rangetop is to be replaced. There is no drawer.

Depending on the cooktop model you choose and its ventilation requirements, You may have to remove the drawer box for the top drawer in a 3 drawer cabinet. This might be the case if you choose to replace the existing cabinet with a drawer unit.

If you keep the door cabinet you have, you may be able to use a fold open sink base drawer to add a little storage.

@wdccruise - I was responding to the person who seemed to be accusing you of "cherry picking" cooktops that wouldn't allow a drawer under the cooktop and suggesting the OP could have a drawer added in the space. Based on my research late last year, most induction cooktops do not allow a functional drawer in the "top drawer space".

Wow. This community is amazing. Thank you all for your thoughts.

The model we are putting in is a Frigidaire

https://www.frigidaire.com/en/p/kitchen/cooktops/induction-cooktops/FCCI3627AB

Someone else suggested that we buy a 42"w x 24"d x 1.5"h piece of butcher block and cut out the space for the new unit. We'd have to support the butcher block 'frame' of course, because it will, in turn, support the cooktop. Our mockup looks like this.

Thoughts?

It’s resourceful! But I don’t see it provides a solution to the front of the cabinet once you remove the existing unit. And I would be concerned about grease staining the wood that close to a cooktop. Also wonder if you have to keep a perimeter of non flammable material around the cooktop? I realize induction heats the pan and not the work surface, but wonder about radiant heat. Not setting the wood on fire, but discoloring?

I actually have a gas Chambers and I am going to be putting this in a new kitchen and I am not 100% sure I want to commit to it long term so I had a drawer front that inserts into the space made by the cabinet maker, should I want to convert to a more modern gas or induction unit in the future without redoing the kitchen.

It will not be hard for someone to make a shaker drawer front to match and paint it to match, and then you can sort out fixing the counter.

Our you could have a stainless steel counter piece made to fit the old Chambers hole, that had a properly sized opening for the new cooktop to sit in it.

There are a number of ways you could go with this, all custom of some sort but reasonable types of site specific modifications rather than reinventing the wheel.

Is there a reason you are giving up on the Chambers?

The thing that I like about mine in concept is that there are no electronics at all. I am just a little worried about having a pilot light, but I am not sure that's all that rational of a worry.

I like your backsplash. It looks like you already have wooden accents in your kitchen so I think the butcher block would go with the look. (I also like the idea of getting a “trim” piece of stainless made. So I am not really that much help!)

What if you replaced all of the countertop that is under the vent hood with butcher block? (From the door frame to where the backsplash has a little shift forward.). The left side would be easy enough. But I am not sure how difficult it would be to cut on the right side.

Just another idea.

"The model we are putting in is a Frigidaire https://www.frigidaire.com/en/p/kitchen/cooktops/induction-cooktops/FCCI3627AB"

I wouldn't choose that model because (a) the largest element is 8" and (b) it has digital controls. I think the Frigidaire FPIC3677RF which has control knobs and a 10" element is a better choice ($2150 at Appliances Connection).

The installation instructions state that the cooktop should not be placed closer than 2" to a "combustible wall". I don't know whether butcherblock is combustible but there would be no space between it and the cooktop. Wouldn't the butcherblock be filthy after awhile? Also, you didn't propose a solution for the gap in the front of the the cabinet that would be created when you removed the old rangetop.

IMO anything other than replacing the countertop to fit the cooktop would look, well, like a kluge.

I agree with wdcruise

People use butcherblocks around cooktops all the time. Our induction cooktop is in a Walnut counter and it looks brand new years later. Seriously, when you spill something, just wipe it up. It really isn’t any more difficult to clean than any other surface, and can be easily restored. It does require a bit more regular maintenance, but as long as it is maintained it works fine. Wood is actually durable enough to even be used on floors!

I think butcherblock is the perfect solution. Just make sure the shop will do an apron front butcherblock, so you might need to find a local woodworker, but it is not hard.

Alternatively, stainless steel will work fine. Stainless counter cutouts are always wrapped around wood so a stainless steel counter with a stainless steel apron will give plenty of support.

Alternatively, you can add a short cabinet box to the top and have a new paint matched door made. Or have a contrasting door made. Or have the doors below replaced with taller doors. However, none of these solutions fix the top and bottom simultaneously, which butcherblock and stainless can.

Good luck

ETA: trim pieces don’t really need to support the cooktop. Cooktop installation and trimming the install, are separate problems. While solutions like butcherblock and stainless steel might integrate both, it isn’t necessary. A support frame can easily be constructed and then trimmed out.

A combustible wall is not the same as a combustible countertop. Wood with laminate has been widely used for years, and only presents problems when a red hot pan is set down on it. It is rising flames (and hot oven exhaust when ranges are involved) that are potentially an issue for combustible walls. With induction, this would be a flambé issue for most circumstances, but with gas one has a repetitive potential degradation of the combustible materials.

It looks like Miele makes a 42" induction. Did you consider that?

Thanks, all! This gives us enough to go on. I'll let you know how it goes!

@latifolia: "It looks like Miele makes a 42" induction."

That requires a 40-3/4" cutout. The rangetop cutout is 42" wide, the same width of the proposed cooktop. The cooktop needs to overlap the countertop.

"That requires a 40-3/4" cutout. The rangetop cutout is 42" wide, the same width of the proposed cooktop. The cooktop needs to overlap the countertop"

But now we're talking a simple stainless steel collar to span smaller gaps. My cooktop installer had a buddy fabricate a stainless collar for my Wolf cooktop, which is about an inch & a half shorter lengthwise than my cutout. Works fine.

Here is a picture of the stainless steel cooktop collar my installer had made. It looks just like the ones you can purchase from Microtrim or Summit. I paid about $275 for it in 2021. Some might quibble over the aesthetics; I just wanted a solution for a too large cut out in my stainless steel countertop.

Here's what the installer did underneath. He screwed the wood blocks into the cabinet sides. There are 6 total. The blocks support the metal collar. The brackets supplied by Wolf for the cooktop tighten into the collar & merely prevent the cooktop from sliding around. The brackets don't support the weight of the cooktop. Only the glass lip around the cooktop that rests on the collar provides support. That's the way my old glass cooktop was supported too.

As for the open area above the cabinet doors where the old controls were, others here have given some good suggestions.

@awm03: "But now we're talking a simple stainless steel collar to span smaller gaps."

That Miele KM637742 Inch Induction Cooktop is a whopping $4700. She proposes to install the Frigidaire FCCI3627AB which sells for $1200. I suspect that she can replace the countertop for less than $3500 + $275 = $3750.

Glad you found a solution!

Looks great!