New construction is the easiest point to get a steam shower right, because nothing has to be undone. The walls are open, the circuits aren’t set, and the plumbing runs are still lines on a drawing. Make the decisions below in the right order and a steam shower becomes a wellness feature buyers can feel on the first walkthrough, without stretching the schedule or surprising the budget.
Originally published April 2019
Thought this guide was first published in 2019, it has been fully updated to reflect MrSteam’s current generators, controls, steam heads, and packages, so you’re not working from specs that are several product generations old.
In this guideFour things: where the generator goes, what electrical circuit it needs, how the plumbing and drains are routed, and where the control, steam head, and bench sit on the wall. All four are cheap to decide on a drawing and expensive to change once the drywall is up.
The generator lives outside the steam shower, as close to it as practical, and never inside it. The limit is 60 feet of separation between the generator and the steam shower, and a 30-foot control cable comes in the box, with a 60-foot cable available. On a new build, the usual homes for it are a linen or utility closet, the inside of a vanity, the cavity of a sealed bench, a heated attic, or the basement mechanical area. Wherever it goes, leave a way to reach it, because someone will need access for service.
Size affects where it fits. A standard MS generator is about 14.5 by 14.75 by 6.75 inches, roughly the size of a briefcase. The larger MAX generators (MX4, MX5, and MX6) run about 28 inches wide and should not go in a vanity or any other tight space.
A dedicated 240V circuit is standard, with 208V in some homes, sized to the generator you choose. The draw scales with capacity, from 21 amps for the smallest MS generator to 125 amps for the largest MAX. Size the generator first (next section), then let the electrician size the circuit to it.
Plan three connections: a water feed to the generator, a steam line from the generator to the steam head, and a drain from the generator. The piping has to be brass or copper; PVC and PEX aren’t rated for the job. Standard sizes are a 3/8-inch NPT water feed, a 3/4-inch NPT steam line, and a 1/2-inch NPT drain (1 inch on MAX generators).
Give the steam line a slope of 3/4 inch per foot, running either toward the steam head or back to the generator, so condensate has somewhere to go instead of sitting in the line. Insulate long runs. Where possible, add a pressure-reducing valve that holds incoming water between 15 and 25 PSI. Keep the generator drain and the drip-pan drain plumbed separately.
On opposite walls. The steam head goes low, above the finished floor at the height specified in the selected steam head’s installation manual, aimed away from where a person sits. The control goes 4 to 5 feet up, near the bench, on the wall opposite the steam head, where it reads the room’s temperature instead of the steam plume. If you include a bench, build it 18 inches high and 15 inches deep, opposite the steam head. The reasoning behind each placement is laid out in The Anatomy of a Steam Shower.
Size it to the room’s adjusted volume, not its raw dimensions. MrSteam’s SmartSizing method does this in three steps, and your blueprints already hold every number you need, even before the shower is built.
Here’s how much the finish choice matters on the same room:
| Room | Adjusted volume | Generator |
|---|---|---|
| 5 × 4 × 8 ft, porcelain tile | 160 cu. ft. | MS225R (108–161 cu. ft.) |
| 5 × 4 × 8 ft, marble | 160 × 1.5 = 240 cu. ft. | MS400R (162–257 cu. ft.) |
Getting it right matters in both. A generator that’s too small can’t bring the room up to temperature, so sessions feel weak and the homeowner assumes the product is at fault. One that’s too big costs more up front and needs a larger circuit than the room calls for. MrSteam’s VirtualSpa runs the SmartSizing math for you and produces the technical specs you’ll need when ordering.
Planning a compact shower?For guest baths, starter homes, and compact showers, the Steam@Home line is 23% more compact and fits showers from roughly 3 by 3 up to 3 by 5 feet. Note the warranty difference when you spec it: MS, Super, and MAX residential generators carry a limited lifetime warranty, and Steam@Home generators carry a limited one-year warranty.
Every system comes down to four layers: a generator, a control, a steam head, and optional therapies and accessories. Here’s the current lineup for each. Several products named in the 2019 version of this guide are no longer mad and they’ve been replaced below.
MrSteam makes four residential controls today. The control drives both the experience and the price, so match it to the buyer you’re building for.
iSteamXa 7-inch touchscreen that runs steam, AromaSteam, ChromaTherapy, AudioX, and the SpaH2O shower valve from one screen. The pick for buyers who want everything.
TempoFlexthe only wireless control, with no communication cable running to the generator. Range is up to 60 feet from its receiver, and wall construction affects that, so test the placement during install.
iTempothe classic flush-mounted digital control, available in 13 designer finishes.
TempoTouchthe simplest option, a tactile touch arc for setting temperature.
When you’re choosing, look into how Extell Development handled controls at One57, the “billionaires’ building.” The developers opted for the simplest possible controls “so that even infrequent users will find them a breeze to use.” Individual homeowners may want more.
These turn the steam shower into a true spa experience, and two of them need rough-in work that’s far easier with the walls open.
It’s most efficient to add these now rather than later, when installing them would disrupt the homeowner:
MrSteam makes three towel warmer collections: Metro, Broadway, and Tribeca. All three are hard-wired to 120V, so add them to the electrician’s rough-in list. They’re built to warm towels, FYI, not dry wet ones.
Most residential projects start with a spa package, which bundles a control, steam head, and accessories for less than buying them separately. The current packages, from richest to simplest, are Bliss, XDream, XButler, ButlerFlex, Basic Butler, and Butler Touch, plus the Steam@Home package for compact spaces. Because they span budgets, one plan set can carry steam across several price points in the same community.
Seal it, waterproof it, and keep the steam where it belongs. A steam shower has to be a completely enclosed room, because any gap lets steam escape into the bathroom.
In new construction you choose the conditions. In a remodel you work around them.
With the walls open, you can put the generator exactly where service access is easiest, run a straight steam line at the right pitch, and pull a dedicated circuit sized to the generator. You can also frame for a Linear SteamHead, a ChromaTherapy fixture, and AudioX speakers before anything closes. In a remodel, each of those becomes a question of what the existing walls, ceiling, and electrical panel allow. That’s where the wireless TempoFlex earns its keep, since it skips the control wire run entirely. In new construction, any of the four controls is an easy run.
A licensed plumber and a licensed electrician, ideally ones who have installed MrSteam before. The plumber connects the water feed, the steam line, and the drain. The electrician wires the dedicated circuit and breaker.
Installation referenceMrSteam’s Quick Set Up Guide is an overview, not an installation manual. The actual install should follow the product’s Installation, Operation & Maintenance Manual, which you’ll find on the Residential Guides & Specs page.
Your next buildSize the system in MrSteam’s VirtualSpa, pull the specs from Residential Guides & Specs, or visit a dealer showroom to see the products in person. For the full planning picture, download The Ultimate Guide for Planning Your Home Steam Shower.
Yes, as of September 2026. This guide was originally written in 2019 and has been updated to MrSteam’s current lineup. The AirTempo control is now the TempoFlex, and the packages, controls, and steam heads above reflect what MrSteam makes today.
Usually not by much, when the key decisions are made before framing. Generator location, the electrical circuit, and the plumbing runs fold into the rough-in work that’s already on the schedule. Most delays come from deciding late and opening finished walls.
Up to 60 feet. The generator should sit as close as practical, never inside the steam shower, and somewhere a technician can reach it for service.
Not in a home. An 8-foot ceiling is optimal and a residential steam shower doesn’t need a sloped ceiling. Ceilings above 8 feet increase the generator size you’ll need.