DH here. Conventional wood framing, then hardbacker, which adjoined to the rest of the hardbacker that formed the shower walls. In other words, the niche is simply part of the wall. Warning -- if possible, frame the niche at least 2 inches larger than your desired final niche opening dimensions, and don't seal with Hardibacker, nor sparkle with thin-set, until your tiler does the actual tile layout measurements. Depending upon where the tile lines lay, you may want to add layers of Hardibacker to fill so that you don't have to notch tiles at the corners. Then, we waterproofed the entire hardbacker surface (walls and nook) using three coats of Laticrete's Hydroban product (rolls on like thick goopy paint, dries to form a rubber-like seal). According to our tiler, if/when water gets behind the tile (wall or nook), it slides down the Hydroban and exits into the tub. Had to shim walls to make sure the Inside edge of the Hardibacker overhangs the raised lip of the tub, so that water sliding down behind the tile exits inside the lip of the tub. Apparently, an alternative to shimming the studs is to notch the framing so the tub lip sinks into the framing by 1/4", which lets the Hardibacker's inside edge sit inside the lip of the tub. That also helps the tiler bring the tile down inside the tub lip without angling the last row of tile in to clear the lip.

I second Bill's advice above. Ideally, a solid stone shelf is the way to go. We have this in our master bath and love it. We had it placed about 1' to the right of hte main shower spray to minimize the amount of water that could wash into it. With that being said, our kids' baths have niches with 4x4 tile as the shelf and we have had no issues. But I also attribute that to using the little clear flexible soap holders with the little tines on them to keep the soap off the tile & placing the niches on the back wall of the tub (farthest away from the water) to minimize the amount of water that gets into the niche in the first place. I much prefer a niche when you have the option of doing one over those racks that go over the shower arm/attach with suction cups to the wall or having the ceramic soap dish/shelf that protrudes from the wall. Hope this helps!

....it only looks like that since you pointed it out. Anyone else would be looking at what you put on the shelf. How many people are viewing your shower niche on a daily basis? Don't mess with the grout, unless you want to paint it pink.... I hope you will smile every time you walk in there and think of a cream sandwich. IT makes that shower YOURS. I have one grout line in my shower that is larger than the others. No one in the whole world will see it and say gee, that line is wider than the others... Relax and I hope you will enjoy your new shower, w/o getting hungry whenever you shower! -Babka

There was a thread on this topic some months ago--see below. There are some good photos of niches. Our project is bogged down, but I have a few additional comments since I posted... Because we have to watch our pennies, I'm shopping in bargain places. One problem I have encountered is that oddball lots of tiles often don't include bullnose pieces as well as regular field tile sizes. The niche that we have roughed in will require some cute tricks to make ordinary tile edges seem attractive and classy; we don't want to just snip tiles and leave raw edges. DH, my sweaty equity, did not finish the niche smoothly when he created it in drywall because we knew we would cover it in tile. Now, we're thinking that we might not do the tiling right away and he'll have to pull out drywall tools and make a proper corner edging around the niche. This kind of "go back and do over" gig is getting very frustrating. [Meanwhile, I've found a smashingly exciting tile that of course only comes without trim pieces. It's sitting right next to me, thinking. Unfortunately it has a decidedly unfinished raw edge and will require tricky handling if we choose to use it. I just covered it over so I can't see it tempting me there on the table. Have to be more practical. ] Tile shops do carry a metal edging that can be used to finish off edges when no bullnose is available, but I haven't seen examples of it in actual use on a range niche. Would love to see a sample photo to reassure me. Also, remember that if you choose to work with a thick tile or a remnant of some kind of rock from countertop on the back of the niche, that will cut down the depth of the niche shelf. If you want the area above range/cooktop to be an artistic focal point, I humbly suggest that you either make a niche OR some kind of tile design but not both. If you choose too fancy a niche back, the items standing within the niche will compete with the tile design for viewer's attention. Mine will be a working kitchen, so we're planning to put oil bottles, vinegar bottles, salt shaker, etc. there and they are supposed to get top billing. Don't forget that you can suspend a second shelf in the niche if there's room. Here is a link that might be useful: Niche topic thread