With outdoor showers springing up on apartment rooftops and hotel terraces as the sexiest new amenity to take Manhattan, more New Yorkers are relishing their last few weeks of summer by rinsing off in the great outdoors.

“The urban appeal is growing. I would say it’s a definite upward trend,” the author of “The Outdoor Shower: Creative Design Ideas for Backyard Living, from the Functional to the Fantastic,” Ethan Fierro, said.

At Blue, a new condominium at 105 Norfolk St., the 14th-floor unit boasts an outdoor shower on its 950-square-foot terrace. Because the building is many stories higher than anything else around it, the resident will have a variety of views, the marketing and sales agent of the 32-unit building, Barrie Mandel, said. “It’s a loft that has a lot of sizzle to it,” Ms. Mandel said of the unit, which had an asking price of $3.25 million. It closed this month. Two more apartments at the building, on the 15th floor and the penthouse on the 16th floor — neither of which has an outdoor shower — will be available for purchase in mid-September, Ms. Mandel, a senior vice president at the Corcoran Group, said. The remainder of the building is sold out.

A penthouse apartment at 147 Waverly Place also has an outdoor shower. The unit, which sold more than a year ago for $10 million after five potential buyers locked horns in a bidding war, has a 1,100-square-foot terrace, the broker of the building, Sean Turner, said. It also boasts a private party room and a hot tub. Because residents may want to use the hot tub in the summer heat, the architects believed it would be beneficial to equip the penthouse with an outdoor shower so residents could cool off, Ms. Turner, executive vice president at Stribling Marketing Associates, said, adding that the building has “extraordinary views — especially of the Village.”

From past experience with other penthouse sales, Ms. Turner said that if amenities such as hot tubs and outdoor showers are not included, the buyers often want to install them later.

“You might as well put it in now rather than going back,” she said.

At Sky Lofts at 145 Hudson St., the penthouse has just been redesigned to include an outdoor shower. “It will have a built-in privacy area as well,” Ms. Turner, who is also a broker for the listing, said. It is going on the market in October, with an asking price of more than $30 million, and is scheduled to be completed by December.

Another new development at Times Square, 1600 Broadway, will have an outdoor shower on its rooftop observatory deck.

Outdoor showers certainly raise the desirability of an apartment. “It’s a necessity — we all basically have to get clean sooner or later and the outdoor shower bridges those worlds of necessity and pleasure,” Mr. Fierro said.

Outdoor showers are not exclusive to Manhattan. At the Galaxy, at 5-03 50th Ave. at 5th St. in Long Island City, the developer decided to include outdoor showers on the rooftop to create a tropical atmosphere. The showers should be ready within six months, in time to cool off its residents next summer. The building is fully sold and prices ranged from $636,000 to $998,000. In addition to the showers, the 12-unit building will include a synthetic path, landscaping, and cabanas to “get that beach vibe going on the rooftop,” the sales and marketing director of the building, Rick Rosa, said.

Mr. Rosa, originally from Miami, said the building can “be brought to a new level” by adding particular features. Because the Galaxy does not have a number of luxurious amenities — such as a health club, doorman, or concierge — Mr. Rosa said he hopes to capitalize on the rooftop.

Mr. Rosa is working on another building, the Solarium at 5-39 48th Ave., also in Long Island City, which will also feature outdoor showers in an effort to bring a Miami feel and lifestyle to New York.

It isn’t just residential buildings that are jumping on the outdoor shower craze.

The Bowery Hotel at Bowery and Third St. in NoHo has an outdoor showerhead on the terraces of each of its seven one-bedroom terrace suites. The Maritime Hotel, on Ninth Avenue, boasts an outdoor shower on the terrace of its penthouse suite.

Mr. Fierro, who has built more than a dozen outdoor showers in Martha’s Vineyard, where he grew up, and Maui, Hawaii, where he currently resides, said there’s a wide range of outdoor showers.

“It typically comes down to the architecture to make it high-end or simple,” he said.

The growing popularity of outdoor showers in New York City could be due to residents’ feeling out of touch with their environment, he said.
“In urban situations we go from inside the house to the office to the store, all in an air-conditioned or heated environment,” Mr. Fierro said. “Showering outside is a way that we are able to connect … it just feels good and it’s beautiful to look out at the scenery, the steam in the air, the landscaping, the cityscape.”