You should check on the electrical forum but they definitely can extend the boxes to be flush with the new backsplash.

Alternatively, an electrician can easily pull one outlet up to under upper cabinet height and you can wire in plugmold, thus avoiding any holes in your backsplash. In addition, having an electrician do this may be cheaper than paying for him to pull out all the boxes to the right depth and also paying for each cut out.

Chances are, your full-height backsplash will be 2cm stone. There's no reason to spend the extra amount it would cost to use 3cm on the backsplash.

That being said, there's no need to reset the electrical boxes. As long as the holes cut into the stone are sized and positioned properly, the metal "ears" at the top and bottom of the electrical receptacles will rest on the edge of the stone and can be screwed down tightly (although slightly longer screws may be needed). Once the cover plates are in place, the "ears" will be covered and all will look and function just as it should.

I don't agree with what jamesk said about it being 2cm. Usually, it will be the same thickness as your counter granite because it comes off the same slabs. 2 cm stone might be cheaper than 3 cm but if the counters are going to be 3 cm, it might be difficult to find a color match and impossible to find a grain match in a 2 cm slab.

Ours is 2 cm because that is what our counters are (and what most stone is around here).

gneegirl, our electrical boxes were installed as kevin described. Our granite fabricator cut the holes for the outlets and switches when he came to install the backsplash. The cutting was done in our back yard. I think our outlet boxes are also a kind that lets the box depth be adjusted with a couple of screws though that isn't essential.

We got Lutron outlets and switches in a color that went well with our granite (black but the Lutron "satin" black is less shiny than the ones at the hardware store - close to a matte). We splurged and got granite wall plates made from some of our left over granite by Columbia Gorge Stoneworks. One end of the backsplash is next to our back door and has a bank of six switches for various internal and external lights so the granite wall plates make a difference.

We are quite happy with the results:

Here is how it looked before the granite wall plates arrived:

Here is a link that might be useful: Columbia Gorge Stoneworks

Not to belabor the point, the the other principal reason that 2cm stone is usually used for backsplash instead of 3cm stone (even if the countertops are 3cm), is that it's much easier to integrate with moldings and other trim which might abutt with it. 3cm stone would be thicker than most window or door moldings, making the transition between trim and the stone awkward.

Here's an image of of a portion of my kitchen with 3cm countertops and 2cm backsplash. The eye usually won't readily detect slight variations between two pieces of stone (assuming they're very similar) if one is on a horizontal plane and the other is on a vertical plane. Naturally, a skilled fabricator helps, too.

My original point about it not being necessary to reset the electrical boxes would be true regardless of which thickness of stone was used.

WOW - you all have great info and it now makes sense to me. I'm talking to the fabricator in the AM and will find out about the thickness of the backsplash. I may need to push the install date up a day or two because of other stuff - sink and faucet, so I may have time to have the electrican move the wires up the wall so I can have plugmolds. If not, I'll use the other approach - leaving them in place but adjusting them for the backsplash thickness. Thank you so much for all the details - VERY HELPFUL. I'm almost there!!!!

gng