Set on 6.3 oceanfront acres in Malibu, Calif., the 16,107-square-foot estate La Villa Contenta is lavish even by local standards. Built in 2002, the stately family home of developer Richard Weintraub has a timeless presence—from its Kentia-palm forest and landscaped gardens to the antique-marble pietra dura mosaic in the entryway.

Although quite regal—with significant architectural details in every room—the four-bedroom, 12,000-square-foot main house still feels like a home. Rare antiques furnish the double…