Maybe fire danger? I have no clue. We agonized over how high over the cook top to put our micro-hood, and that has nothing to do with depth of cabinets, but when cooking, there is always a danger of fire, and if the cabinet sticks out over all the burners, maybe grease splatters could catch the cabinet wood on fire? Manufacturers worry about that stuff.

Our uppers are the typical 13", and the above is just an opinion.

Suzi

I'd never heard this, so I checked the installation manual for my induction cooktop, the KitchenAid (don't get one of these!). It said that cabinet depth of 13" was "recommended." It also said on a different page that there should be no cabinet overhead "in order to avoid burns and fire caused by reaching up" into the cabinet. But if you wanted a cabinet, then it was OK as long as you had a hood that extended out at least 5" past the cabinet, since then presumably you would not be able to just stretch up into the cabinet and burn yourself. (This is classic corporate CYA.). So if your hood were 22", you could have a 17" deep storage cab over it. I realize not all cooktops have the same requirements, but did you actually check the exact language in the installation guide? I don't know if going against "recommended" is enough to void a warranty. And if you're putting in what is basically a hood surround, that isn't the same as a storage cab.

The idea that your clothes could catch on fire from reaching over an induction cooktop is kind of laughable. You'd have to really try hard. I suppose you could burn yourself if you dipped your clothes into hot fat or boiling water on the stove, but you don't need to reach into an overhead cabinet to do that. (I have small scars from hot olive oil splatters.) Maybe this language is left over from gas cooktops. I'm surprised the instructions don't just say "Be careful! Cooking can be dangerous! For maximum safety, don't cook!""