When the Broadway set designer, John H. Young, affixed his name to a four-story studio in 1904, in what today is known as West Chelsea, it was surrounded by warehouses and horse stables.

It was the ideal location for him to create meticulous backdrops and props for plays by Florenz Ziegfeld, George M. Cohan and other marquee names, away from the bustle of the theater district.

Now the narrow strip of 29th Street, between 10th and 11th avenues, is chockablock with luxury apartments, and the whir-bang of construction in nearby Hudson Yards signals more to come. So the roughly 6,400-square-foot building is listed for $18.5 million, in part because recent zoning allows roughly 18,500 square feet to be developed on the lot. The property taxes are $42,790 a year.

But the current owners, artists themselves, looking to spare Young’s studio from the wrecking ball, are hoping its quirky interior may be enough to deter speculators.

“I would cry if someone tore down the building,” said Nadine Knudsen, who, along with her business partners, moved their fashion and textiles business into the building at 536 West 29th Street about 20 years ago, and bought it in 2008, after a complicated lease agreement with the previous owner. City records show a $500,000 transaction, but she said millions were spent to bring the commercial space into good condition.

Why the bother?

“Walking through that front door is like: Wham,” said Ms. Knudsen, who was in awe of the 34-foot-high ceilings, across a 25-foot-wide expanse without a single vertical column. “It’s like a fantasy for a designer,” who can configure the space in seemingly endless permutations.

Oversize windows pour in northern light, prized by photographers. The absence of pillars, designed so that Mr. Young could rig massive scrims from the ceiling, allows for flexibility in reconfiguring the space. Currently it’s divided into a fashion studio on the lower level; a kitchen with over 20-foot ceilings on the mezzanine that leads to a terrace overlooking a 750-square-foot private garden; a combined great room and dining area; a top-floor library, two bedrooms, four bathrooms and an office.

“It had to be someone who had courage and stupidity combined,” said Ms. Knudsen, who spent over a decade adding modern features and peeling back layers of midcentury faux pas.

The red brick walls, which now have a mottled, blue-grey patina, were buried under years of white paint. “We were buying cookies for every neighbor,” she said of the prolonged restoration, and the loud whiz of the paint-removal tools. (Those neighbors, a church and a private investigation firm, have left or are in the process of leaving, as developers swoop in.)

Even though the studio is dwarfed by nearby mid-rises, two large skylights brighten the interior, and they are aided by glass and glass-like cutouts in parts of the floor that give lower levels a solarium quality. Because of the unusual floor plan, visitors can look straight through the skylight from the first-floor den, more than 30 feet below.

Relics of the past are venerated in the rear garden, which is decorated with giant gears that were once part of a pulley system for hauling stage settings. Mr. Young, whose best-known scenes were produced around 1900 to 1915, was praised for his deft “mechanical displays,” like a scene involving a race between trains and motorcars, according to his 1944 obituary.

A trap door in the floor, used by a previous owner and photographer, still functions.

Ms. Knudsen, who has split her time between this space and a home near San Francisco, has left her own mark. The master bedroom has 13-foot wooden doors that were salvaged from a convent’s motherhouse in California. The upstairs library is made of walnut wood that was crafted and sourced from upstate New York.

The rear private garden has a mature cherry tree and organic soil that Ms. Knudsen shipped from Maine, because it had bits of colorful seashells and peat. “You have no idea you’re in New York,” while in the garden, she said — with the occasional exception of clanging construction nearby. To counter the changes around her, she installed Cor-ten steel walls on three sides of the garden, which rust to a bark-like color and add privacy to the space.

Ms. Knudsen and her partners are selling the property because they are winding down their fashion business and plan to spend more time in California.

A sale at this price, on this once largely commercial stretch, would have been unthinkable several years ago.

“This was a very industrial, gritty neighborhood, right up until the 1970s,” said Tom Miller, an architectural historian who writes the Daytonian in Manhattan blog.

That time is over. Just down the block, at Soori High Line, a luxury condo where several units have indoor saltwater pools, the developer was recently seeking $22.5 million for a penthouse apartment.

A few blocks away, at the Getty, a new luxury apartment building, a penthouse closed for over $59 million last year, a downtown record, said Jonathan J. Miller, the president of the real estate appraisal firm Miller Samuel.

Erin Boisson Aries, an associate broker with Christie’s International Real Estate’s New York brokerage, said part of the appeal of the building was its development potential. The 6,400-square-foot structure can be expanded to more than 12,000 square feet, and the purchase of additional air rights from the city would allow for roughly 18,500 square feet, she said. The facade, which still bears Mr. Young’s name, is not protected by landmark status. Ms. Aries shares the listing with Nic Bottero, also with Christie’s.

Ms. Knudsen remains hopeful that the next buyer will see value in its already flexible floor plan. “It would be sad to see another part of New York die,” she said.

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