Bumping in hopes of receiving non-spam responses.

We put in a steam unit in a shower smaller than that size (55 x 36) when we did what you are doing (changing from a tub/shower combo to a shower only in the master) and are putting in another one in a new build in a slightly larger shower (66 x 48). Obviously we (mostly my husband) are fans of at-home steam! I think your shower size will be fine; in fact, you don't want too big a shower relative to the power of the steam unit and especially not too high a ceiling -- in the new build we are bringing down the shower ceiling from the rest of the bathrooms 10 ft height to make it better for steam.)

We are also in an area of high-priced housing(for our area) and the designer we used opined that if you can't have a large master bath (with shower and separate tub), you should go for the wow shower. When I try to sell in a year, I guess I'll find out if she was right!

I'm curious what will cost $2200-$2500 above the cost of the generator versus the cost of a non-steam shower?

What do you mean by "worth it"?

If you like steam showers and are willing to spend $2,500+ for that luxury, go for it.

If you are wondering if this "investment" will pay off when you sell, there is about a 99% chance it won't. Almost no renovation projects make money and splurging on high end finishes make that even less likely.

Steam showers have to be built to be water vapor proof, not just waterproof. It's more involved construction involved. You can't just take a shower and fully enclose it and add a steam generator and have a steam shower unless you want to have rot and mold behind your walls in a hurry.

I don't the exact size of my parent's steam shower but I know it's not that big. It's a molded unit and there is seat at each end w/ the steam unit in the center. It's maybe the size of 2 of the basic stand up shower units (?)
I suppose it could be bigger but it's good enough.
They have absolutely LOVED their shower and use it almost daily. Nothing beats a steam shower, especially when you're feeling under the weather. I always use it whenever I visit.
My husband and I have already decided when we build our house, a steam shower is an absolute must! Neither of us are bath people so, for us, those fancy whirlpool tubs would be an absolute waste of money.

I decided to go for it. I could not turn down a $2700 Thermasol generator on sale for $540. Standards of Excellence in San Marcos has 3 left if anyone else in So. Cal. is interested. Sunday is the last day the store is open.

My GC said the extra work consists of: running a 240v power line from the panel to the steam unit; plumbing in a water feed line to the unit, a steam output line in to shower and a drain line for the unit in the attic. In addition to hooking up the unit, the ceiling would need to be water proofed and sloped so cold condensation on the ceiling does not drip onto us. Tile on ceiling. Installation of high output vent fan in steam shower so all the steam gets vented out and not trapped in the bathroom. A full glass enclosure with a tilting glass top vent. Water and vapor proof entire enclosure.

By "worth it" I mostly meant would it be enjoyable to steam in a shower that size. I know I will not get back most of the cost on resale, but I plan to be in this house for 20+ years.

Enjoy!

My steam shower was 4'x6' and that's about the right size for 2 people in my opinion. Since it's mainly going to be just you using it, your size should be fine.

About the sloped ceiling: ours was sloped too but condensation dripped quite a bit from the grouted area where the tiles were joined. If you can do larger tiles, perhaps you won't have that issue.

We pulled a teak bench into the shower when we wanted to use the steam. We also didn't have a vent.

Are you sure your local code will allow a fan to be installed inside the shower? It's against code in my town to do so, and not really necessary anyway as all the steam dissipates almost immediately when the door is open. A good fan in the bathroom is sufficient.

Lovely bathroom, Annkathryn. I wanted my GC to give me a rough idea of extra costs before I bought the generator, but I may push back on a couple of items when it is time to actually build it.

Our entire bathroom is long and narrow. It is 13.5' long, and 6' wide, except for the last 42" where it is 5' wide in the shower area. You enter from the bedroom at one short end, the first 6' is a double vanity, then there is a wall with a pocket door, then the toilet (going to be wall hung with tank in wall to save space), then the shower. So the toilet and shower are in the same space that can be closed off from the rest of the bathroom. I planned to put a Panasonic Whisper Warm fan just outside the shower in the toilet area. I hope that will be sufficient to clear any steam, as I do not really want a vent fan in the shower itself. We also have a small window in the shower that we leave open about 10 months of the year to get fresh air in the bathroom, so I can just open it back up after a steam. Except in December and January, we usually shower with the window open, so I am not sure we need a tilting glass vent to avoid showering in an air tight space. I'll have to find out how much extra that vent will cost.

Any update on your steam shower? You got an incredible bargain on your steam unit, how could you not have gone for it?

Any further comments you might have would be useful to others, especially to me as I plan our steam shower (same size as yours) for an addition to the house we're starting this spring.