When Kirk Ferguson asked Sara Story to design the interiors of his new house in Austin, Texas, his request was unlike any she had heard before.

“He wanted something like an opium den,” said Ms. Story, who spent much of her childhood in Texas but is now based in New York. “He really wanted a place with a ’70s vibe, and groovy.”

Mr. Ferguson and Ms. Story had been friends for years, and after talking more about what the house could become, they arrived at a design concept. “It sounds a little silly,” said Mr. Ferguson, 55. “But it was Lenny Kravitz meets Italian ’60s meets ‘Once Upon a Time … in Hollywood.’”

It all started when Mr. Ferguson, who worked in investment management in New York but now focuses his energy on projects related to the arts, wildlife conservation and health and wellness, decided to move his primary residence to Texas. He bought a recently built modern house of about 5,000 square feet on a hillside on the outskirts of Austin, paying about $6 million in the fall of 2021.

The concrete, metal and glass structure, designed by Ravel Architecture, reminded him of the Case Study Houses that modernist architects like Richard Neutra and Pierre Koenig built in Los Angeles in the mid 20th century. And its long views across a canyon to the city center reminded him of the Hollywood Hills, a favorite place.

“It’s basically a glass-and-concrete box on stilts, hanging off the side of a cliff, looking over the city of Austin,” Mr. Ferguson said. “That spoke to my design sensibility.”

But the minimalist interior didn’t feel like the kind of place where he belonged. “That’s where Sara came in,” he said.

Ms. Story, who is used to working with eye-catching art and design, and bold colors and patterns, was surprised by how energetic Mr. Ferguson wanted to make things.

“So much of the time, people want to play it safe,” she said. “But he was always asking for more color and more pattern. He really pushed me out of my comfort zone.”

By the time they were finished, they had filled the home with visual surprises. The most audacious room may be the bar and lounge facing the pool. Previously a crisp white box, its walls are now covered by a mural of thick yellow, orange and brown curving lines painted by Caroline Lizarraga.

On one side, Ms. Story installed a curvy 1970s chrome bar by Willy Rizzo, which she bought from an antiques dealer in Belgium. On the other, she installed a custom sectional sofa covered in gold velvet inside a niche lined in mercury mirror.

In the living room, she put a B&B Italia Camaleonda sectional at the center of the space, with seating on all sides, envisioning it as an inverted conversation pit.

To create a media room, she enclosed a covered patio with glass, wallpapering the ceiling with a design of hand-painted dots from Porter Teleo and adding a shaggy faux-fur rug under a sinuous coffee table sculpted from a tree trunk by Adam Birch, a South African artist.

In the primary bedroom, she placed a plump custom-made bed against a wall painted with another mural by Ms. Lizarraga, this one with smoky ribbons that curl up from the wall onto the ceiling. At the windows, Ms. Story added ombré wool-and-cashmere curtains over lacy gold-and-purple sheers that she had made from a fashion fabric found in Manhattan’s garment district.

For the three other bedrooms — one for each of Mr. Ferguson’s three grown children when they visit — she selected a different graphic wallpaper to animate the space. Finally, in the powder room, she added Londubh Studio wallpaper with mushroom shapes outlined in shiny gold.

The interiors were completed in about six months, just in time to be photographed for Ms. Story’s new book, “The Art of Home,” published this month by Rizzoli. The cost, Mr. Ferguson estimated, was more than $1 million, but he and Ms. Story continue to look for unique pieces to add to the mix.

“I’m very happy,” he said. “It’s a great place to have people over, have a cocktail and watch the sun go down.”

Ms. Story’s design has resulted in just one problem. “I realized she’d done such a great job that I’m a little reluctant to have parties to mess it up,” Mr. Ferguson said with a laugh. “Maybe it should have been done in a way that was a little less amazing.”

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