Induction Cooking:
Replacing Existing Combination Stoves

Problems and Solutions For Over- and Under-Counter Usage

The Problem

Many who are interested in replacing existing cooking equipment with induction gear have a mechanical problem with the available space in their kitchens.

If you are designing a new house, or doing a major kitchen overhaul--which is effectively the same thing--you can plan out and design in whatever equipment you please. But if you are working with an existing kitchen for which you do not want to do a major upgrade, there can be problems. That will be especially so if what you want to replace is what is called a "slide-in" combination unit--that is, a single integral piece of equipment with a cooktop surface and oven under it. Such "slide-in" (or "combination") units (see image at right) are usually a stock size, either 30 inches wide or, sometimes, 36 inches wide.

There are, for now, no combination units made with an induction cooktop. (That is not exactly true, in that there are some few large, expensive units made for which you can get a partially induction cooking surface installed, but it is wildly unlikely that one of those is what you would be looking at as a simple replacement--plus we strenuously deprecate "mixed" cooktop surfaces.)

That is no longer strictly true: Diva de Provence has finally released its long-announced induction-topped range. The problem is that it is being sold at about $9,500, which is not realistic for most homeowners (even if there are big discounts, that's still a mighty big ticket.)

Now it might seem that the simple alternative would be to get a stock undercounter cabinet (of the sorts available at all home-supply stores) of the wanted width--let's use 30 inches for discussion purposes--put a 30-inch-wide induction cooktop on it, and slip it in where the old slide-in went. In most cases, you think, you could even put an oven in under the cooktop. But, with only a couple of exceptions, that won't work. Here's why:

Most induction cooktops exceed their nominal width. Of the "30-inch" and "36-inch" units available in North America (that is, omitting the "domino" one- and two-element units), the actual widths of almost all exceed their nominal size. Now that part is not so bad: one could let the unit top lap over the edges of the cabinet and just slide it in a hair over the countertop surface till full in place, then let it down--mildly annoying but not a big deal. The real problem comes under the countertop.

A cabinet that is 30 inches wide outside has wood walls with non-zero thicknesses; typically, such walls are each 3/4" thick. That means that the interior width of a "30-inch" cabinet is usually 28½ inches wall to wall (and of a 36-inch cabinet, 34½ inches). The problem is that the required "cutout" (width of the actual cut in the top surface into which the cooktop will drop) for so-called "30-inch" cooktops is--for almost all current North American units--more than 28½ inches--usually by a good bit (anywhere from 1/10 inch up to 1-1/4 inches wider); and the same applies for so-called "36-inch" units. In other, simpler words:

Almost no "30-inch" cooktop will fit into a 30-inch undercounter kitchen cabinet, and ditto the 36-inch'ers..

Till very recently, that "Almost" was No, but the new GE and Wolf units can now fit, if only just barely, into correspondingly sized stock base cabinets. But that is only 6 units, 15% or so of the current marketplace.

Some enterprising--one might say "fanatic"--souls have modified stock 30-inch cabinets by shaving away the inner walls at their top few inches, down to a wall thickness of 1/4 inch or so, so as to be able to fit a cooktop in; their theory, probably correct, is that the walls of the adjacent cabinets will provide support, especially if the "shaved" cabinet is screwed to them below the shaved area. We do not recommend such an approach, which would not be for everyone anyway.)

Here is a table showing the widths of all currently available units, in alphabetical order; the workable ones for base cabinetry are in boldface.

A Solution

Though there are "fittable" units in the table above--including some excellent values--if you want some other unit but face the existing-space limitations, there are ways to work around the problem, given a little ingenuity. They require somewhat more work and expense, but a lot less than a total kitchen makeover.

Your old slide-in unit will have some other cabinetry on one or both sides of it--perhaps something like this:

Let's assume we are speaking of a 30-inch-wide slide-in, and that the adjoining cabinets happen to each be 18 inches wide (the details are not critical--this is just for illustrative purposes). You take out one of the adjoining cabinets, say the left-hand one. Then you replace it with one 6 inches narrower--in this case, 12 inches wide. Then you get an stock 36-inch stove undercounter cabinet. Now you have something like this:

With a 36-inch-wide stove-type cabinet, you have all the room in the world to install your new "30-inch" induction cooktop. (And if your old slide-in was 36 inches wide, you just get a 42-inch stove cabinet.)

Are there minuses? Sure, a few. First, as the coloration above hints, you may not be able to match the finish of your existing cabinetry with the new units, as to either exact appearance, exact trim (handles and suchlike), or exact color. Still, with some care you can usually come pretty close on all counts (see graphic at left); or you could simply make the new units very different in color, so they just form a little block of their own and don't look like a faked match. Second, you do lose 6 inches of cabinet width. Third, you have the extra expense of removing the old and installing the new adjacent cabinet (the materials cost is really not much--it's mostly the labor).

You also don't have to worry too much about matching the surfaces of the new cabinet units to your existing countertop. Perhaps the easiest thing to do is use tile for the area, as it's nice to have tile around a cooking surface so that you can put hot pots down; the cost is not great for the small amount of area involved (recall that the cooktop itself covers much of the new surface).

You also have to custom-mount an oven under the cooktop, and take some care that the two are compatible as to spacing requirements. Many cooktops have related ovens with which they match up well, but in general there is not usually a problem unless the oven is somewhat over-size. Of course, if you're replacing an old slide-in you'll be replacing your oven anyway, even if you were merely getting a new slide-in. Whether the new oven comes as part of an integral unit or as a separate item is immaterial, save that when it is separate you can shop for it separately, and get whatever make and model best pleases you instead of whatever might come attached to a particular cooking surface.

This matter of the oven deserves some further comment. The fact is that there is no good reason why your oven should be under your cooktop, and many good reasons why it shouldn't. The only reason it ever is placed there is for the convenience of those who make combination units--not for those who have to use them. If you install cabinetry something like that described above, and leave the oven out of it, you have 36 inches (or 42 inches, as may be) of new storage space; that allows you to find a spot in your kitchen where you can place an oven as a wall-mount oven without, on the whole, giving up any precious storage space--what you use up for the oven is quite made up for by the space under the cooktop, and that will even include the 6 inches you stole from the adjoining cabinet. And take it from us: if you have been used to using an under-counter oven, you will be nothing short of ecstatic at the pleasure of using a convenient-height wall oven instead. It is so much easier to work with--and for your knees and back!--that you will wonder how you ever got on with the old stoop-down-to-use kind.