There’s a New Menace Stalking Suburbia. Meet the McBasement.

When Sterling McDavid’s parents bought a roughly 9,000-square-foot home on Aspen’s Red Mountain, the 33-year-old interior designer directed the architect and contractors to start digging.

Limited by zoning above ground, Ms. McDavid, who led the renovation, envisioned an expansive basement with a world-class gym, guest suites and hotel-caliber spa for her parents, former college track star Stacie McDavid, and David McDavid, a former owner of the Dallas Mavericks and car-dealership mogul.

“I love a basement,” says Ms. McDavid, who ultimately blew out her parents’ basement to more than double its size. “When you walk into a home, if all the magic is just within the first few steps, that’s no fun.”

Wealthy Londoners have long built basements reaching two, three, and even four stories below ground. Now, there is a cellars market in the U.S. among property owners facing restrictions on mansion sizes above ground. The McBasements of today have bars, bowling alleys, pools, climbing walls and whiskey-tasting rooms. To sidestep subterranean gloom, builders usher in natural light via grand staircases or skylights cut into the ground above.

“Down is the new up,” says Randy Correll, partner at Robert A.M. Stern Architects, who designs basements with luxe finishes. “Twenty years ago, basements were the ‘B word.’”

Ms. McDavid says the excavation for her parent’s 4,000-square-foot Aspen basement added about a year to the three-year renovation, since workers dug underneath the home and into a mountainside. The resulting basement has guest suites, a gym with white oak floors, a 12-person hot tub and an “absurdly large” steam room, she says. “You feel like you’re in a luxury cave.”

She says the prior owner, by contrast, had done little to maximise the basement, which was “absolutely heinous.” (“It had wine storage, not to be confused with a wine cellar,” she says.)

Still, some towns have cracked down on the chic crypts, worried about unsettling topography and having truckloads of excavated dirt roll through residential streets. In Aspen, a resident sued the city for permitting a neighbour’s two-story basement, alleging excessive noise and dust. Aspen now limits basements to one level. And the Beverly Hills Planning Commission is now mired in a down-and-dirty basement brouhaha.

The island of Nantucket, just 14 miles long and 3.5 miles wide, limits home sizes with more than 20 zoning districts. Some areas allow a footprint covering only 2 percent of the property.

One solution? Go low. “The possibilities are endless,” says Stephen Cheney, owner of Cheney Custom Homes, who is currently constructing a roughly 16,000-square-foot home and guest home with a 5,600-square-foot “bunker” below for a bowling alley, 3-D golf simulator, and spa.

Basements can dwarf homes above. Designer Andrew Kotchen, a principal at Workshop/APD, is working on a 5,000-square-foot Nantucket abode that will have a 10,000-square-foot basement with a basketball court, garage, bedrooms and a wellness space.

In beach towns, architects are deploying extreme waterproofing measures.

For the 10,000-square-foot grotto, workers are using the same waterproofing technique as Boston’s Big Dig highway project, Mr. Kotchen says. An emergency pump system and thick concrete slab underneath will prevent the foundation from floating up should water levels rise, he says.

In Aspen, a 5,000-square-foot basement at the confluence of two rivers required “dewatering,” says Ryan Walterscheid, a partner at architecture firm Forum Phi. Workers drilled wells around the site and pumped out almost a billion gallons of water before pouring the foundation. (The water was poured back into the river.)

Architect Charles Cunniffe, who designed the McDavids’ remodel, also did a basement with a tennis court. “You can’t hit big lob shots,” he says, “but you can play a decent game of tennis.”

Interior designer Bryan Graybill says a large basement at his home in East Hampton, N.Y., was the only way to fit all the amenities he and his husband desired in their 4,100-square-foot house. For frequent hosting, their 1,800-square-foot lower level has full guest quarters, a laundry room with three sets of washers and dryers, and a catering pantry with extra stemware and service for 48. “It’s like an instant party,” he says.

Beverly Hills residents are also keeping up, and down, with the neighbours.

Architect Paul McClean crafted a house there with 7,400 square feet above ground and another 12,000 below, including a 3,000-square-foot garage. The firm also designed developer Nile Niami’s roughly 105,000-square-foot Los Angeles megamansion “The One,” where about half the home sat below grade. First listed at $500 million, the property fetched $126 million at auction this year. (A relative bargain-basement deal.)

Beverly Hills leaders passed ordinances in recent years in response to what Craig Corman, former Planning Commission chairman, called a “pernicious” trend of mammoth dwellings with wedding cake-style retaining walls and massive basements. “They can be quite offensive,” he said during a recent commission meeting. Now, property owners in the Hillside area cannot remove more than 3,000 cubic yards of earth without special permits.

This has hampered real-estate investor David Taban, who is trying to build a 23,144-square-foot house, of which 9,829 would be a basement. (He wants to dig down to appease neighbours who worried his home would hurt their views.) But getting a basement of that size required removing 5,346 cubic yards of dirt, which one city planner said would amount to 594 truckloads.

“Violence to the land,” Planning Commission Chair Myra Demeter dubbed it at an August meeting.

Asked to revise, Mr. Taban’s team is set to return to the commission Thursday. As of late September, plans called for removing just 3,276 cubic yards of soil, according to attorney Ronald Richards, a representative for Mr. Taban, who also argued the project should be permitted since the proposal predates some restrictive rules.

“It’s not even that crazy of a project in our mind,” says Russell Linch, another Taban representative.

Spec developers know the more liveable space, the bigger the price tag, says Brett Loehmann, a project manager at McClean Design. “If you don’t have great amenities, you’re not going to be the coolest person on the block.”

There is ample and alarming evidence that artificial intelligence can help humans do bad things, such as committing cyberattacks, building weapons and even killing themselves or others. The Hugging Face hacking episode—and a growing list of others by poorly constrained swarms of agents—indicate just how powerful and potentially dangerous AI has quickly become.

Yet many inside the U.S. AI industry insist far worse is coming, on account of the imminent arrival of AI with superhuman and self-improving abilities.

Plenty of experts, including many who study AI harms for a living, are skeptical. The so-called doomers’ assertion that AI might decide to wipe out all of humanity—or even “just” topple human civilization—is contingent on it achieving a pace of development not yet seen.

And if the assumptions behind this global-doomsday scenario are wrong, it could lead us to curb or regulate AI in ways that don’t address its real harms.

At the center of this debate is the claim that current AI systems might take over the job of training their next versions, a process called “recursive self-improvement.” Think of it like evolution on steroids—billions of years happening at light speed within vast AI supercomputers. Anthropic Chief Executive Dario Amodei recently proposed a global agreement to slow down the pace of releasing new AI models, with the goal of delaying the arrival of recursive self-improvement.

“I don’t think we’re anywhere near ‘artificial general intelligence,’” says Melanie Mitchell, a professor at the nonprofit research group Santa Fe Institute who studies AI. She said AI is making impressive strides but thinks claims by engineers that they’ve achieved recursive self-improvement don’t stand up to scrutiny.

She is hardly alone. A recent paper by two dozen academics at Princeton, Stanford and other institutions found that even the most cutting-edge AIs are incapable of doing the original research required to advance the AI frontier.

Two of the authors involved in that paper also threw cold water on the idea that the Hugging Face swarm hack by OpenAI agents occurred because of a breakthrough in intelligence. The attack succeeded primarily because of a lack of basic technical guardrails, not an unmanageable explosion in AI capability, they wrote.

Yann LeCun, former chief AI scientist at Meta, posted that this analysis was “a welcome dose of sanity in an otherwise insane debate.”

OpenAI and Anthropic didn’t respond to several requests for comment.

The people who disagree with the doomers still consider AI to be dangerous, and point out that such systems don’t have to be particularly capable to be powerful. Some argue that AI should undergo regular evaluation by outsiders and that the companies that make it should be held responsible when their systems do harm. AI should also be treated the same as airplanes and elevators, and should be designed to do the least harm possible, they say.

“If you believe that technology is powerful enough to create novel, dangerous viruses, or to essentially take over the whole planet for some reason, then it must also be strong enough to create cures for cancer, to cure aging, to fix socio-economic or political problems,” says Christopher Canal, CEO of EquiStamp, a company that helps companies and governments evaluate AIs.

AI has shown an ability to rapidly advance because it is matching the abilities of humans who are constantly feeding it their knowledge. Sometimes it can recombine that knowledge and exceed what people have been capable of, through a kind of post-training known as reinforcement learning, as we’ve seen in mathematics.

Today’s LLMs are “models of knowledge” rather than actually intelligent, wrote Yi Ma, professor of AI at Hong Kong University.

Researchers at universities and commercial AI research labs in China wrote in a recent paper that autonomous, self-improving AI is likely to be a long way off, due to the sheer number of breakthroughs required. They also argue that humans will probably remain in the loop, supervising that process—and gating how fast it can occur.

Vals AI, a company that evaluates today’s AI models, maintains an RSI Index that benchmarks whether models can “do the research that builds the next model.” So far, no publicly released model is even close.

Yet Rayan Krishnan, CEO of Vals AI, says his team projects models will exceed humans’ ability to improve the next generation of AIs by August 2027, or sooner, and at that point could start building their successors all on their own.

“Once we get to recursive self-improvement, the fear is that all bets are off,” he says. “You could end up with a ‘fast takeoff’ situation, where the models quickly acquire skills and eclipse humans across every possible domain.”

In a reply to the resignation tweet heard round the world from Jacob Coxon, another Anthropic engineer declared his belief that those odds were at least 10% over the next decade. Many others in the industry chimed in to say they thought the percentage was even higher.

Some who argue the end is nigh say they calculate their personal p(doom) based on a chain of conditional probabilities—a bit like the Drake equation for calculating the likelihood of intelligent alien life. Since all those probabilities are based on speculation, estimates range from 0% to nearly 100%. Many land around 10%.

“The weird thing is that if you go back and look at the predictions on this over the last 10 years or more, it’s always been 10%—it’s just a nice round number,” says Mitchell. “I think it’s all vibes, and there’s no actual evidence or calculation.”

One argument against worrying about superintelligent AI is that the world is full of unlikely humanity-ending disasters, and trying to avert them all can make it impossible to prioritize, says Canal.

This has led AI experts and the policymakers who listen to them to propose remedies that don’t get at its real and present dangers.

AI companies’ proposals to “pace the frontier” aren’t addressing the problem in the right way, argues Stuart Russell, a computer-science professor at the University of California, Berkeley, and the president of the International Association for Safe and Ethical Artificial Intelligence.

“It’s like saying we’re driving toward the cliff at 60 miles per hour and we’re going to drive toward it at 40 miles per hour instead, and everything will be OK,” he says.

Russell and his peers have proposed that AI companies should have to meet the same standards that govern other areas of everyday life, from air travel and buildings to food and drugs. They highlight the “behavioral red lines” AI should not be allowed to cross. Breaking into other computer systems, stealing information or advising terrorists on how to build biological weapons are all illegal for a human to do, and should be illegal for companies’ AIs as well, he argues.

The challenge for AI companies in such a proposal, he adds, is that it would be a de facto ban on today’s advanced AI systems, since the companies behind them don’t know how to make them respect such boundaries all of the time.

Others have proposed something like the Food and Drug Administration, but for AI, but setting up a new agency has so far been a nonstarter in Congress. And some prominent voices in tech have said such a structure would give up America’s AI edge to China.

Given the bipartisan groundswell of support for curbing AI companies and their creations, however, that may soon change.

“The tech industry has had this mantra for decades that regulation is bad,” says Russell. “They don’t accept the liability for any harm, and they hide behind free speech. That, I think, has to change.”

There’s a New Menace Stalking Suburbia. Meet the McBasement.

Limits on above-ground mansion sizes lead to mammoth grottos with tennis courts and whiskey-tasting rooms. Beverly Hills pushes back: `Violence against the land’

Could fears of an AI apocalypse be distracting us from the dangers already here? Experts debate whether regulation should focus on speculative existential threats or present-day harms, including cyberattacks, weapons and unsafe autonomous agents. Read more via the link in bio.