frankly... your contractor... I'm not sure if is a contractor, I design kitchen everyday...a 27" oven probably required 25-1/2" opening (a Bosch oven that came in my mind). so if you have a cabinet that is large 27" it will fit...but I design italian kitchen... I don't know traditional... but for my experience is the same.
the only thing is the height some built-in oven they don't fit is base cabients.

My 30" oven is in a 30" cabinet. And I worry about the cabinets if removing the face frame would destroy the integrity of them!! What kind are they....what are the sides made of? My cabinets are framless...there is no face frame at all and they are very strong without that face so I can't imagine why he's say that?

The sides of the cabinets are MDF, and the face frame is maple. They are made by American Woodmark. If they cut the face frame to fit the wall oven, there will only be like 1/4 inch overlap of frame left on the sides. Also, this oven cabinet will be installed next to a wall, so there will be a one inch spacer to its left, then the wall, and a 18 inch cabinet to its right.

According to the specs of the cabinet company and the appliance specs, it 'should' work. My contractor has an assistant who has installed kitchens for years, and they are both telling me the same thing - that if they cut the cabinet that close to the frame, that it will fall apart.

Any more advice?

Your contractor is an idiot. Get rid of him right now. The cutout dimensions of your oven are what are important, not the exterior dimensions. Wall ovens sit on the platform inside the cabinet, they are not "hung" from the cabinet. Trimming the frame slightly (if needed, check the cutout dimensions) will be just fine.

But, really, starting out an install like this doesn't give me much confidence in Mr. Years of Experience. Sounds like BS to me. IF he's so experienced, what's he doing as a second banana to an inexperienced contractor, and I'd guess, both of them working for Home Depot? I know times are tough, but geez.

Frameless cabinets have sides that are 3/4" so you get a 25.5" opening in a 27" cabinet. Face frames are usually 1.5" so the opening would only be 24". I know that framed cabinets depend on the face frame for strength and stability. You may still be able to cut into though. Have you thought about getting a 2nd opinion from a cabinet building or woodworking site? It's probably been done before and maybe someone could share their experience with you.

I double checked my oven specs, and it is asking for 24 5/8 cutout. The sides of the cabinet are 1/2 inch thick. So there would be 1 3/16 inches of face frame on each side attached to that 1/2 inch. Is that enough to stabilize the cabinet? Vertically, we need at 27 3/16 inch cutout. I'm attaching a link with my oven specs

Here is a link that might be useful: oven installation specs

You're taking less than half an inch from each frame. I don't see how that's going to compromise the cabinet strength, especially since it's only a single oven, not a double.

Talking to my contractor this morning, it is becoming more clear that his primary concern is trying to screw the oven to the front of such a thin face frame. His concern is that when i use the oven, that the face frame might crack and cause the oven to tip out. What should we do?? Thanks!

The issue is not so much the width or height but the depth. At 24-1/2" the whole back of the cabinet must be removed. The primary strength then comes from the attachment to the adjacent cabinet units. Run screws to secure the face frame to the adjacent cabinet and wall. With an adequate base, it is not going anywhere.

Also does your contractor know that there has to be a 6- 1/2" minimum distance from the top of your counter to the top of your oven? (Shown on the last page of the specs) You will need a dummy drawer front to fill it, and your oven drawer will be lower than the one shown in arbordomus' photo.

-Babka

Do believe you will find the 6-1/2 is a distance for side cabinets when using a gas cook top to allow clearance for piping.

I have found it a waste of money to use a base cabinet when mounting under the sink. A 30 inch will fit in a 30 inch opening as will a 27 in a 27.

It is very cost effective to build the bottom support at the heigth required, use facing filler material above and below as needed. (available from cabinet maker)

Pew1- I'm referring to the dimensions on page 9. I have an electric cooktop and a Bosch wall oven and was required to have that space.

I hate it because it lowers the oven by that distance and I have to get on my knees to see through the window.

-Babka

Perhaps he does not have the skill to trim off the 1/2" needed per side? I know my contractor had told me it's very dangerous for them to trim small sections because they cannot hold to either side--but I was thinking he meant more in the ballpark of 1/4" or even 1/8". I find when a contractor does not have a needed skill, they will make some excuse to do it a different way.

If I were you, I'd discuss it with your kitchen designer who sold you the cabinets. Any way you slice it, you are talking about a cabinet modification and the work both needs to be warranteed and someone accountable for replacement of the cabinet if it does not work. My guess is that the contractor is concerned he will botch the job and so be held responsible for replacing it. What you don't want to happen is be in the middle of a finger pointing situation between the installer, kitchen designer and you in the middle. Who is responsible?

Thanks for all the replies -

I can understand why people are suspecting my contractor of ignorance. That can happen, but I don't believe it to be the case this time. I think he is making sure I am happy with the outcome and have a oven that won't tip or tear out cabinet face frame. Maybe he is being over cautious....

It sounds like it is possible to just set the 27 inch oven on top of a base support instead of IN a 27 inch cabinet - is this correct? Then use some filler pieces if there is any space left exposed, right?

Ok, so how would you secure the oven if you are NOT screwing clips to the face frame. If we were to anchor it to the back of the wall, it would certainly be secure, BUT, if the oven ever needed servicing or removal, would we have to remove our granite counter to get at it? Also, what should we do about supporting the granite counter above? Should we use the MDF vertical cabinet sides on either side of the oven??

I'm not at all concerned about the cost of the cabinet. It was only $130, then Home Depot gave me another $50 off when I asked about the problem with their cabinet specs.

My only concerns are making sure the oven is secure with support for the granite. This oven will be adjacent to a wall, so it is at the end of a line of countertop.

Any wall oven merely sits on the platform and is only safety restrained by the screws of the anti tip mechanism (holes on the side into the face frame.) Of course you can build your own oven surround with fillers and with your own platform rather than use the oven cabinet that you've already bought, but well, you've already bought it. It's really NOT a big deal to shave off a teensy bit of the face frame (or fillers) to get the oven in there. The weight of the oven is on the platform, NOT carried by the face frame. Even if you have granite countertops, a tiny bit removed from the face frame to fit the oven in will not affect the ability of the cabinet to properly support granite as long as the sides are left full height and there is support at the back of the cabinet.