Homeowners are increasingly requesting steam showers when they do bathroom renovations, says Robert D. Henry, a New York architect who has designed a number of professional spas.

“At least 60 to 70 percent of the homes we’re designing now have home spas to some degree,” he says. “People want to integrate these spa features into their own bathrooms.”

A steam shower, or a shower enhanced with a steam generator, can be a great investment for homeowners planning to sell, says Paul Zweben, an associate broker with Douglas Elliman Real Estate in Manhattan, N.Y.

“You’re at least going to get your money out of it,” he says, if not more. During showings, he adds, “When you say there’s a steam shower, most people say, ‘That’s so awesome. I can’t wait to try it.’ ”

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But adding steam to your bathroom isn’t quite as simple as installing a generator that can push hot, humid air into the room. You need a dedicated space, usually enclosed in tile and glass to contain the steam.

Waterproofing is an issue with any shower, Henry says, but it’s even more of a concern in a steam shower.

“You have additional problems because steam penetrates even more than water,” he says. “You have to counter that with really sophisticated waterproofing. Otherwise, you’ll get mold.”

The ceiling should be sloped to keep condensation from raining down on occupants, and the enclosure should include some kind of seating for extended steam sessions.

You’ll have to find somewhere to hide the steam generator, a boxy unit that needs to be connected to electricity and a water line.

“Ideally,” he says, “it should be placed as close to the shower or steam room as it can be, in an adjacent closet or cabinet, for example.”