“It has this exclusivity, but you’re not paying it,” he said.

What holds value is not a bonanza of amenities; it’s classic design and a sense of history.

The ultraluxury units that appreciated at the highest rates from 2007 to 2017 were in classic Manhattan buildings like the Dakota and the San Remo, said Nancy Wu , an economist at StreetEasy. New condos have appeared on the list but have dropped off.

But core amenities still matter. Ms. Wu said the top five — doorman, elevator, laundry, roof deck and gym — added about 20 percent to the purchase price and 20 to 30 percent to the rent an owner can charge.

Breaking out the value of other amenities, though, is difficult, Ms. Wu said. “It’s hard to say which amenity is adding or taking away value because there are often so many amenities bundled together,” she said. “If they have a climbing wall, they probably have a yoga studio, too.”

She said there was one exception: Private elevators, which let owners zip up to their penthouses without mingling with the masses, are highly sought after.

Other privacy perks are popping up. In the New Orleans development, Mr. Friedman added a private package room, so neither the pizza boy nor the FedEx delivery man would have a window into the lives of the residents.

But it’s worth noting that tastes change. Pools, while essential in Miami or Los Angeles, may be making less of a splash in New York. Ian Bruce Eichner , a Manhattan developer and the founder of the Continuum Company, said he had to choose between a pool and a parking garage for Madison Square Park Tower on East 22nd Street.