Thanks Cheerpeople. :) I went out to the new house and they were painting, so it was looking like a "real" house now, which gave me a much better perspective. Armed with tape measure and my circle of cardboard, I determined the diameter is fine. But as justgotabeme was saying, what surrounds it makes a difference. The lights would be next to a short wall from the ceiling because the room behind it has pony walls and open walls. But the "pony" wall continues at the ceiling and comes down 17" ish. That means the semi-mount fixture would hang almost as low as the end of that wall, and I'm afraid it will look too crowded. So I think the flush-mount is the way to go. I really do like the semi-flush one, but this area is adjacent to the foyer, which is going to have two very large chandeliers, and I don't want it to be so completely busy with multiple conflicting hanging fixtures that compete with each other! Thanks everyone, I really appreciate all the help.

The valve is right behind the joystick (single-lever handle). The cartridge is there too, inside the valve body, and it's removable and replaceable once you unscrew the escutcheon (round plate) that the joystick comes out of. Not a big deal. Wall mounts are what they are. It wouldn't worry me. Are you working with copper plumbing? Pex plumbing? CPVC plumbing? Some other kind? They are all good. Use good materials. When in doubt, use the better of two choices. Do a good job. That's all. Sleep tight. I opened the PDF on the Kohler site. The escutcheon is 2-5/8" (6.7 cm) diameter, and it's only 2â³ (5.1 cm) diameter for the valve with single-lever handle. Personally I'd like a One-Inch (1" or less than 26mm) cartridge for my next wall mount project. If anyone knows of one, holler back please.

I did this - I used liquid nails for mirrors, bought at Home Depot. Here are before and after pics. I also painted the vanity and the cultured marble countertop, applied a top coat of marine grade polyurethane. This was done 2 years ago as a quick facelift, it still looks the same, has held up well! We are planning to replace the vanity and flooring next year, but it made the bathroom less ugly for the meantime. As far as how-to goes, I had to remove the clips and shoot some of the mirror adhesive down the back, replace the clips overnight to let the adhesive set (now glued to the wall). Then remove all the clips, make sure mirror is really secure and then glue the wood to the mirror. I used crown molding for the top. I chose to do square corners not mitered because the crown at the top was not a miter join (though it was a mitered cut to look right). Before After

The important distance to consider is the distance between the center of the vanity to the center of one sink. That distance never changes regardless of the size of the mirror. The wider the mirror, the less distance you have between the sconce and the mirror. If my calculation is right based on the measurements you gave, that distance is 21" (please confirm it as I don't explicitly see it on the measurements you gave us). The distance between the edge of the sconce and the edge of the 24" mirror is 6.25". This number came from that calculation: 21" -2.75" (half the width of the sconce) - 12 (half the width of a 24" wide mirror) = 6.25". Now if you use a 36" mirror, the distance between the edge of the sconce to the edge of the mirror would be .25" ( 21" - 2.75 - 18"). You don't want a quarter in. wall between the sconce and the mirror. If you were to find a 28" wide mirror, that distance would be 4.25" ( 21" - 2.75 - 14"). I think the width of the sconce is more in proportion with a 24" mirror. I also think a 24" mirror looks nicer with a 27.5 wide cabinet below it.