It's no secret owners of high-end homes often treat themselves to luxury items like hot tubs. But as The Wall Street Journal reports, a hot tub alone no longer fits the bill.

The trend has transitioned from a simple soak to an all-out spa experience, with everything from massage rooms to saunas making their way into high-end houses. This is good news, especially for retailers who rely on spa sales as their primary source of revenue. It's even more significant for the ones who have added saunas to their inventory.

Experts suggest the growing interest is thanks, in part, to the increasing number of luxury spas that began popping up in hotels 15 years ago. WSJ staffer Candace Taylor zeroes in on a luxe trend:

Saunas and hot tubs have long been fixtures in high-end homes and in the common areas of large condominiums. But as more people consider spa treatments essential to health and well-being—as well as a fun way to entertain guests—wealthy homeowners are willing to pay a large premium to access the whole menu at home. Private, in-home spas with specialized features like massage rooms, pedicure chairs and hammams are becoming more common, spacious and luxurious.Read More