You Know Him From N.B.A. Games. You Know His House From ‘Selling Sunset.’

For half a century, James Goldstein has been renovating a house by John Lautner. It’s a spectacular legacy. But like everything about Goldstein, it’s complicated.

Our homes are reflections of ourselves, right? So it makes sense that James Goldstein’s house, hovering over a canyon atop Beverly Hills, Calif., is one of the most strange, fascinating and perplexing architectural projects in the world.

Goldstein, 84, a controversial figure who made his fortune investing in mobile-home parks in California, may be familiar to you. He’s that leathery-skinned, frizzy-haired guy always sitting courtside at N.B.A. games — he attends more than 100 a year. He’s that guy who shows up at all the fashion shows in Paris and Milan, with a couture-meets-cowboy look, often punctuated with snakeskin hats, colorful leather jackets and a woman more than half a century younger than he is. And he’s that guy who owns the Sheats-Goldstein house — a stunning landmark by the architect John Lautner, fusing prehistory and futurism, solidity and weightlessness, inside and outside, that has been a set piece for films (“The Big Lebowski,” “Charlie’s Angels: Full Throttle”); for the real estate reality show “Selling Sunset”; for countless music videos; and for parties thrown by the likes of Rihanna and the Kardashians.

“The word subtle doesn’t exist for me,” Goldstein said, dressed in all-black tennis gear and a palm tree-emblazoned black jacket. He’s sitting on the sprawling lower terrace of his home’s recently-completed (for now), three-level addition, which is a separate compound overlooking the towers of Century City and, beyond that, the glinting bend of the Pacific Coast.

He calls this undertaking the Goldstein Entertainment Complex, and it also includes Goldstein’s office and a nightclub (yes, you read that right) called Club James, with an infinity-edged tennis court as the roof, made of post-tensioned concrete. Goldstein and his team of architects, builders, engineers and landscape designers have been working on the Lautner house addition since 2003, and that’s just the tip of the iceberg when it comes to Goldstein’s property, which he has been tinkering with for more than 50 years.

Goldstein bought the Sheats-Goldstein house (built in 1963 for Helen and Paul Sheats, an artist and a doctor, and their children) for $182,000 in 1972. Aghast at its cramped feel and banal plaster, stucco and Formica surfaces, he enlisted Lautner himself to help make improvements. Over about 20 years, they removed cluttered divisions and installed frameless glass windows, concrete and wood ceilings, built-in leather-covered furniture and automated skylights.