Instead of going up, mansions go down

Down is the new up when it comes to luxury homes. Or at least that’s what architect Randy Correll said in a recent interview with the Wall Street Journal. Instead of expanding their homes’ footprints or building new floors — sometimes prohibited by local zoning codes or historical designations — wealthy homeowners are building huge basements with amenities that most homeowners can’t even fathom (pun intended).

These aren’t your youth’s musty unfinished basements or dated rumpus rooms. Luxury basements occupy thousands of square feet, sometimes across multiple levels.

Natural light warms the spaces through skylights and staircases, and high-tech engineering keeps Mother Nature out.

When former Dallas Mavericks owner David McDavid and his wife Stacie purchased a 9,000-square-foot Aspen estate, they dug into the mountainside to add a 4,000-square-foot basement at their daughter’s insistence. The new subterranean space has multiple guest suites, a gym, and a vast hot tub and steam room.

On the island of Nantucket, where house footprints are often strictly regulated, another homeowner is constructing a 16,000 square-foot home with an extra 5,600 square feet underneath for a bowling alley, 3-D golf simulator, and spa. Not to be outdone, another new Nantucket build will be a modest 5,000 square feet on the surface, but with 10,000 square feet below to house a basketball court, garage, additional bedrooms, and a bespoke “wellness space.”

And in Beverly Hills, a $500 million mega-mansion boasts about 105,000 total square feet — about half of it below ground.

But while homeowners might love their underground mansions, not everyone feels the same way. Massive basements require noisy, dirty, and prolonged construction, and the neighbors will certainly complain. After a local outcry, the city of Aspen recently limited basements to a paltry single level. And Beverly Hills may never see a 50,000-square-foot basement again — property owners in the Hillside area now need special permits to remove more than 3,000 cubic yards of earth.