The cheapest and easiest solution to warm your bathroom would be to add the heated towel rack and a warming light/vent like the one from panasonic. I would be weary of any contractor that would try and lower your original concrete slab. Once you remove your tile and smooth down the leftover thin set, you glue or tape down the heated flooring mats/wires then cover them with SLC or mortar and let it dry. Then you install your tile or membrane as normal. The added height will be about 1/8". Are you redoing the tile outside the bathroom? Is the same type of tile?

We have a Runtal Solea in our recently remodeled master bath and love it. We're upsizing from the 33" or 34" model to the 54" because it only warms the towel where it is in direct or near direct contact. We'll put the smaller one in our son's/guest bath currently being remodeled. He's pretty happy to be inheriting this little luxury!

No argument heating with electricity is the most efficient? I can't let that statement stand. Let me quote: The efficiency of any system depends on the definition of the boundaries of the system. For an electrical energy customer the efficiency of electric space heating can be 100% because all purchased energy is converted to building heat. However, if the power plant supplying electricity is included, the overall efficiency drops. For example, a fossil-fuelled power plant may only deliver 4 units of electrical energy for every 10 units of fuel energy released. (That's only 40% efficient.) Even with a 100% efficient electric heater, the amount of fuel needed for a given amount of heat is more than if the fuel was burned in a furnace or boiler at the building being heated. If the same fuel could be used for space heating by a consumer, ***it would be more efficient overall to burn the fuel at the end user's building.*** So if your goal, at the end of the day, is to produce the most heat with the least fuel, burning natural gas in a boiler at your house will win over the natural gas-steam turbine plant-electricity-back to heat at your house every time. And I'm reiterating this because there seems to be some sort of disagreement. Also, because for example on the bathrooms forum, I'm surprised at how many people I see installing radiant electric heat systems in their bathroom floors. "Don't they get it," I wonder, "how wasteful it is to heat the space this way". But if there are authoritative voices (like engineers) throwing around terms like "electric heat is 100% efficient", then I can see why they'd make such choices. It's like saying the garbage goes to zero mass after you put it out on your curb for collection and it crosses your property line. Sure, maybe it weighs zero to you once it's gone, but you have to take into account the whole cycle. Same for the electricity you use. If you're only looking at what happens inside your property line, you're not seeing the whole picture. Let's end this thread. I've fallen into one of those gardenweb black holes that I want to avoid. Future comments are welcome of course, but I may not respond, except to those pertaining to the original topic, which was steam towel warmers. Willtv, thank you for your encouraging comment.

Our towel warmer made the towels not quite as toasty as a dryer. So try an experiment: put your towel(s) in the dryer and make them toasty. Then take them out and set them outside your shower. See how warm they are when you finish your shower, assume they'll be a bit less warm/toasty coming off a towel warmer, and judge for yourself whether they retain their heat sufficiently for your needs.