You can simply buy a recessed med cab with this set-up. Or you can take the spec sheet from one you find online that you like and take it to your carpenter, if you like. Metal makes for a thinner wall than wood so leaves you with a deeper interior shelf. Here is a Spec Sheet from one at Signature Hardware.

Ferguson Hardware has this Kohler one with lights in the two side mirrors and an electrical outlet. They also have 16pages of tri-view medicine cabinets, so find one you like and show it to your carpenter. This is the fastest and easiest way to get a diagram of this style of med cab. Just click on where it says "specification sheet" on whatever one you like and save it. They are usually PDF files.

What you're describing is a standard builder grade medicine cabinet available in any big box store.

Decor Planet sells a variety of frameless, multi-mirror, recessed medicine cabinets of the type I think you're describing.

Thanks.I was just looking for woodworking plans, but the specs on one of the cabinets will help. This was a custom built-in-place cabinet. It was not a load bearing wall so he had that wall built differently. It was about 7 ft wide x 3 ft tall, not just built in between wall studs 16" apart. I guess we will have to try to make it ourselves and have the cabinet maker do the exterior finish work. I remember it had movable glass shelves and the mirrors were etched on the perimeter. I don't care about the mirrors though. The builder went from building our little $57,000 house to million dollar homes within ten years because of the little extras and his attention to detail.

http://sofiamedicinecabinets.com/products/index.php?main_page=index&cPath=176_177_182

40" Tall

http://sofiamedicinecabinets.com/products/index.php?main_page=index&cPath=165_167_171

36" Tall

http://sofiamedicinecabinets.com/products/index.php?main_page=index&cPath=92_107_95

30" Tall

Thanks, I will look into them.

Any med cab that is more than 14" wide requires that a carpenter make the studs in the wall "special" like your original house. They simply design the wall supports (studs and headers) to fit around the medicine cabinet. If you look at the triple cabs, you can see that there is no 2" stud between the cabinets. Any wooden cabinet will have a thicker back wall than any metal cabinet, reducing the interior space or forcing the cabinet to protrude further out of the wall to get the same depth. You can chose a cabinet that protrudes out a bit in order to get a deeper, more versatile cabinet, if you do not mind the edge sticking out beyond the wall. I would much rather have that extra depth be usable, not the thickness of a wooden back.

For size, you can also get customized sizing where cabinets can be ganged together. For example, two 12 inch cabinets ganged together or two 15" ganged together would work where you can add lighting as an option and have interchangeable left or right open doors. It gives you alot of storage over your vanity without looking too wide. These can be surface or recessed mounted.

And some of these mirrored medicine cabinets have integrated LED lighting, which can also offer a nightlight with dinner function. So, you will not only have lighting from your main bathroom, but an additional light source. I hope this helps