When Kobi Karp, a Miami-based architect, designs one of the sleek, ultramodern homes that have become his trademark, he thinks about arcs and angles. He thinks about how to fill the houses with so much sun that they become light boxes; he considers the Art Deco heritage of South Beach and the influence of its undulating seashore.

And then he checks his clients’ medical history, to see if they are at risk for cancer or C.O.P.D., for heart attack, seizure or stroke.

Homes designed by Mr. Karp, who also built the flagship 1 Hotel South Beach and a number of Four Seasons hotels, routinely sell for eight figures. They are luxury properties with an added value: Sometimes they can save lives.

That’s because in Mr. Karp’s homes — embedded in the beveled mirrors, tucked among the recessed lighting and hidden under the salvaged-driftwood wall panels and tiled floors — there are dozens of hidden sensors, offering a steady stream of communication on the health and well-being of the occupants.

There is perhaps no real estate buzzword more worn out than wellness, which now seems to apply to any number of features, including yoga rooms, vertical gardens, vitamin C-infused showers and ambient lights. But over the past decade — as wireless-enabled wearable technology has allowed us to track our heart rates and sleep cycles from wristwatches, as artificial intelligence’s capacity has grown exponentially and as smart-home features have become de rigueur — some of the wealthiest homeowners are embracing a new kind of wellness.

This trend, which involves high-priced, high-tech upgrades to bedrooms, bathrooms and kitchen appliances, allows those who can afford it to keep tabs on their health.

“We can use the home to get into your guts, your health and your blood system,” Mr. Karp said.

Mr. Karp’s houses are wired to become smart homes and then fitted with health-tracking devices customized to each client’s needs. Is the homeowner prone to seizures? The floorboards will be lined with sensors, from companies like SilverEco, to detect a sudden fall. Or is he or she diabetic? Mr. Karp might order a specialized bathroom mirror from CareOS, to check the homeowner’s vision.

The collected data is monitored by sites like Home Health Monitoring by Telus and uploaded to cloud-based systems like Truven Health Analytics. From there, it is available to doctors and can even, in the case of a fall or a stroke, be used by emergency medical technicians on the way to the scene.

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Credit…Josh Ritchie for The New York Times

If that sounds futuristic, it’s not. Mr. Karp’s homes are simply another example of something that’s been happening for a while.

In 2017, Google Nest bought Senosis, a digital start-up that offers health monitoring. Amazon Alexa is now HIPAA-compliant, and through the smart speaker’s health-care program, you can schedule appointments, receive lab results and check prescriptions. Companies like Withings, Luna and Sleepace offer sleep sensors, for $25 to $200, that sit under your sheets and monitor your sleep. There are numerous air filters on the market that not only clean your air but alert you to its quality. And the Japanese manufacturer Toto sells toilets that measure urine flow, blood glucose and BMI, for around $25,000; on-site stool analysis is expected next.

There was a time, Mr. Karp said, when homeowners balked at the idea of being monitored 24/7, but that time has passed.

“We used to be concerned about privacy. But today, it’s the reverse,” he said. “In the near future, having a smart home monitor your health will be commonplace.”

Doug Feirstein, 50, agrees. In April, Mr. Feirstein, a founder of Hired Inc., a recruitment company, moved with his family into a 8,400-square-foot home in Fort Lauderdale, Fla., that is outfitted with a full suite of technology from Delos, a wellness real estate brand that Mr. Feirstein decided to invest in after experiencing it himself.

“I have two young kids, and my wife and I wanted to give them not only an environment that is nice to live in, but also one that has the cleanest air, the cleanest water and the right monitoring levels of toxicities,” he said.

When Covid-19 hit just before they moved in, the technology offered comfort, he said: “I felt a sense of security that we were moving into an environment that we could monitor, and if we were going to be in isolation, we knew that we’re isolating in a clean environment.”

Delos, the New York City-based start-up that Mr. Feirstein invested in, has a $1.25 billion valuation and a custom home wellness intelligence technology, called Darwin, that it released in 2018. It has also collaborated with the Mayo Clinic on the Well Living Lab, a research center studying the connection between human health and the spaces we live in.

“We’re all spending over 90 percent of our lives indoors, in our homes, office and schools,” said Paul D. Scialla, the founder and chief executive of Delos. And with Covid-19, Mr. Scialla said, homeowners are monitoring their baseline health with new urgency.

“What this has done,” he said, “is get everyone to understand that what surrounds us matters, what we touch matters, what we breathe matters and how we gather indoors matters.”

Delos also created the WELL Building Standard through a subsidiary, the International WELL Building Institute, and in 2013 built the first WELL-certified condominium complex in New York City. In Tampa, Fla., the nation’s first WELL-certified neighborhood, Water Street Tampa, is under construction.

WELL certification involves measuring air, light, sound and water quality; other requirements, including access to healthy food and green spaces, must also be met. Delos has outfitted and certified buildings including the MGM Grand Hotel in Las Vegas, a public school in Los Angeles and several single-family homes. And a number of new luxury condo complexes — including Villa Valencia in Coral Gables, Fla.; Solemar in Pompano Beach, Fla.; and the Pendry Residences Natirar, in Somerset County, N.J. — will have Darwin technology in every unit.

Credit…Josh Ritchie for The New York Times

“When we were cave men and we lived outside, our bodies and brains were controlled by the sun,” said Jan Vitrofsky, the founder of HEDSouth, a technology company that installs wellness-tracking devices, including Darwin, in custom homes. “Now the air is horrible, and the air inside a space is horrible.”

Among the tools Mr. Vitrofsky uses in his work: air-purification systems that remove impurities, pathogens and (for a steeper price) particles that carry viruses; custom water filters based on local aquifer data; and dawn-simulation lighting that mimics natural sunlight.

Most of Mr. Vitrofsky’s clients are wealthy, but his company’s packages start as low as $2,500 for a simple installation that includes basic lighting, air and water monitoring with Darwin technology. From there, the prices climb exponentially.

Mr. Feirstein, who hired HEDSouth to customize the technology in his home, spent around $300,000. “Doug got the best in class of everything,” Mr. Vitrofsky said.

Since the onset of the pandemic, Mr. Vitrofsky said, he has seen interest in his company’s services more than double. “Whole Foods is wellness, Smartwater is wellness, Equinox gym is wellness — everybody has taken this wellness term to try to sell their product,” he said. “But nobody was talking about wellness on its own. Now the whole world is focused on being healthy, on not wanting to die.”

In Florida, the epicenter of real-estate wellness, some developments are taking health tracking a step further by building homes with private on-site health care. CC Homes, a builder in South Florida, last month announced a partnership with Baptist Health South Florida. Residents of two of its communities, Canarias at Downtown Doral and Maple Ridge at Ave Maria, will receive telemedicine services from Baptist doctors through a health kit that includes HD cameras and infrared thermometers that will check on ears, noses, eyes and lungs, all from within their own homes.

And in downtown Miami, the Legacy Hotel and Residences will include an on-site, AI-powered medical diagnostics center to track residents’ health using body scanning, posture analysis, blood work and more.

“As a society, we’re pretty consistently being told that technology and wearables will produce data about us, and what you can track you can change,” said Noah Waxman, the founder of Cactus, the company building out Legacy’s diagnostics center. “Spaces and places like this one are only becoming more desirable. Because there is no way that in the next five years your phone will be able to do what this diagnostic center can do.”

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