Have you asked your architect?

Is that a closet at the bottom?

We have a wet & dry sauna in our townhouse. Yes-2 saunas. We’ve been in the townhouse more than a year. We haven’t used either one. They sound great, but I really wish I had closets instead. I’m only saying to really think if you will use the sauna vs the cost. Good luck in your choice.

My husband would use a wet sauna every single night if he had one. I know this because he had one for 12 years and it broke his heart to leave it behind when we moved. But it was a large one from Finland (he actually bought it while in Finland and had it shipped to the US) - probably 5' x 5'.

Long way to say - what kind and what size? From personal experience, I know we would use the sauna and never use the bathtub so that's where I'd start figuring on a new plan - removing the tub. Ours was in a walkout lower level, on a slab, so we didn't have to worry about moisture/heat/etc.

Our saunas are both walk in rooms. Wet sauna is stone. The dry sauna is wood They were built for a NBA player. Great multi level seating in both. Wonderful if you use them-

Is this a proposed house? Why do you want a sauna? How do you plan to use it? Do you currently have one? How often have you used one in the past?

Make shower/steam combination it's healthier vs. dry sauna and you don't have to go through a major remodeling.

I don’t agree about the better of the 2 but saunas are easier to put into spaces since they are usually prebuilt. BTW toilet rooms inside a bathroom are just plain silly no one should be using the toilet while someone else is in the bathroom. As for that sauna have you checked out what size would work for you? IMO you need to talk to sauna makers to see what they suggest I usually like saunas or stem rooms in another party of the house instead of the master bathroom. The reason is that they tie up bathroom space for long periods of time so just common sense to not have them in the master bath. I think you need to really think about how much you will use this they are often a wish with no real idea of the use. Sort of like jacuzzi tubs the novelty wears off quickly for some and often not a good resale item

"Make shower/steam combination it's healthier vs. dry sauna and you don't have to go through a major remodeling."

In theory perhaps, in practice not.

People tend to use sauna's (if built properly) much more than steam rooms or turkish baths and people do multiple rounds in saunas which have numerous health benefits, particularly for cardiovascular.

Sauna's are higher heat and that is a big part of the benefit for cardiovascular and dementia.

Turkish baths OTOH appear to be better for skin health and possibly for relief of muscle soreness.

There have been a number of studies by Mayo and others documenting the benefits of sauna (Finnish dry sauna heated by rocks). I am not aware of any documented (vs theoretical) benefit for turkish baths. IR Cabins (called FIR or NIR Sauna in the U.S.) may have some benefits (along w/ some concerns) but we still haven't seen enough studies on these to know. They are not sauna, despite the marketing terminology, but may still prove beneficial in some ways.

OP, a few thoughts if you do a sauna (I'm a fan of them, especially if you live in a colder climate).

- There's a popular saying in Europe that "90% of sauna's in the U.S. are bad and the other 10% are worse". This is primarily due to poor ventilation but also benches too low, temps too low, too few rocks, etc.

- Ventilation is critical. The easiest metric is 6 air changes per hour. So if you have a sauna of 200 cubic feet then you need 20 CFM of ventilation. And it's critical that this flow through the sauna. The ventilation supply should not be from your bathroom or a closet but from outside, a hallway or your bedroom.

- The foot bench (lower bench in the U.S.) should ideally be equal to or above the top of the rocks in the heater. This helps to keep your feet from being too much cooler than your head.

- Consider a more public location. While sauna can be very enjoyable alone or with a partner, it is a great social activity with friends.

- Check saunologia and saunatimes for more info.

It will be good if you look at Am-Finn. They can help you.

I checked out Am-Finn quickly. Good people to avoid. Bad/inaccurate information in the blog posts.

Worst though is quite poor sauna designs. For example, in a sauna the lower bench should be above the top of the stones, the upper bench about 17-18" above that and the ceiling then about 44" above that. The saunas pictured on the Am-Finn website are backwards with benches down low in the cold part of the sauna, an area that you actually want to avoid sitting in.

A new good resource on saunas: http://localmile.org/trumpkins-notes-on-building-a-sauna/