$225 was my cost to get the bigger hole for a replacement cooktop. The appliance store where you buy your new cooktop should be able to schedule the cutout for you.

Beware- it is really messy- the dust gets everywhere even though they used plastic barriers and a vacuum. I ended up washing everything in the kitchen afterwards so do this before you load your cupboards.

Oh yes, also blue tape cover all your drawer glides; the dust may hurt the glides. Better safe than sorry.

Use a good HEPA vacuum on the kitchen afterwards and wipe every surface.

Good luck!

It's more complicated than a hole in the granite. The MW above is too small for a 42" hood. So both of the adjacent cabinets would need to come down. Then the crown would need to be reworked. And the base cabinet below is likely not large enough to house a larger cooktop.

Give a mouse scooter and you have s whole kitchen gut and redo over changing a cooktop.

Keep the same size cooktop for now. Buy one off of Craigslist if that one doesn't work. Save your dollars to put towards the eventual redo and use that cooktop as a goad to your motivation.

Thanks @GreenDesigns -- we've been there before, so we're wary of the Give a Mouse a Cookie Phenomenon. Cooktops appear to be all different shapes, so I think its going to be tough to find one the exact shape. The one in there now only has 4 burners, 3 that work. We really do use the six we have now, so we'd like to size up if possible. As for the hood, maybe we will just leave the microwave for now. That's more of an aesthetic thing for me.

A cooktop wider than the microwave would be a fire hazard. You can't do one thing without doing it all.

It's hard to tell from the angle of the photograph. How wide is the wall cabinet above the microwave? If the 6 burner cook top is 36" and the cabinet above the cook top is 36", you can do it. It's not ideal, but it's workable.

"Does anyone have any experience with this? Will we be able to cut a larger hole in the granite?"

Yes, I cut new appliance openings all the time. If there is "dust everywhere" your tradesperson is not familiar with state-of-the-art Festool equipment. I cut through stone, concrete, and estone dry in million-dollar oceanfront highrises regularly without complaint. There will be a little bit of dust.

"Would we better off pulling out the 36" cabinet entirely and putting in a range?"

My appliance change-out customers are constantly underestimating the amount of work involved. Be comprehensive before you commit.

I am alarmed that the OP and the respondents have ignored Green Designs' warning about the OP keeping the 30" MW over a new 36" cooktop. Even the "Pro" has said nothing.

This is serious.

You will be installing a 36" cooktop with combustible material above it. A fire hazard. I mean it. Don't do it.

I don't think any of the dimensions have been confirmed.

The OP says there is a 36" cabinet for the current cooktop. The OTR MW may be the same size. If so, it's not an issue...not ideal b/c it would be better if it was 6" wider, but not against Code.

Note the OP would like to replace the OTR MW with a true hood.

There was only one or two 36" OTR made. It's a standard 30" with manufacturers metal spacers at the sides. Obvious when you've seen one. That isn't 36".

Ok. So, no word from the OP. (It is a holiday weekend, though.)

If that is only a 30" space, then either the upper cabs flanking the MW need to be removed/modified to fit at least a 36" hood or the replacement cooktop can only be 30" with a 30" hood.

It's probably time to wait for the OP to respond.

Another choice for the OP is to purchase a 30" rangetop instead of a new 36" cooktop. A rangetop provides more cooking real estate than a cooktop because the knobs are not taking up room on the cooking surface. It won't give her 6 burners, but a rangetop will allow all 4 burners to be used with larger pans at the same time, which is not what a 4-burner cooktop will allow. Not many people actually use 6 burners at once, but the extra elbow room is appreciated.

A choice of a rangetop will also be an easier installation, as the cutout is simply the 30" width, and not some specific measurements that are unique to a specific cooktop. And finally, the upper cabinets can remain the same, with no issue of a 36" cooking surface under combustible materials. The only downside is that the OP will have to lose the drawer directly under the cooktop, in order to fit a rangetop. That is still a smaller price to pay compared to reconfiguring the upper cabinets in order to avoid a fire hazard.

You can find a less-expensive 30" rangetop at a scratch-and-dent or display sale, or on Craig's List.

Ugh, I was wrong about the measurements. Just confirmed with the homeowner, the cabinet is only 30".

Sorry-- just catching up on the thread. Thank you to everyone who responded. It is only a 30", which makes it less attractive for us to try to replace at this point. I just don't think we can get that much more cooking space in a 30" cabinet. All the more reason to start planning a large scale reno.... Open to any ideas you all might have!

KL - see my 30" rangetop suggestion I posted above. It will give you more "cooking space in a 30" cabinet" - there is a significant difference from a 30" cooktop where the knobs are taking up a great deal of room.

Otherwise, it makes sense if you want to do nothing until you can do everything at once in a reno.

I'm going to second friedajune. We had a 30" range with knobs on front panel in previous kitchen and now have a 36" with knobs on range top. While I'm not going to say it's the same real estate, I am surprised how much room is saved with knobs in front.