A storied discount department store is putting down roots in a storied Upper West Side building. Loehmann’s is opening its second Manhattan location in the Ansonia Hotel, a beaux-arts tower once home to baseball great Babe Ruth and composer Gustav Mahler.

The Upper West Side store welcomed its first customers over the weekend as part of a soft launch, in advance of the April 11 grand opening. It has been more than a decade since Loehmann’s opened a Manhattan store, though the retailer is now undergoing its first major growth spurt since emerging from bankruptcy in 2000. The Bronx-based seller of men’s, women’s, and children’s apparel is planning to roll out about 40 new stores in next three years — including locations in Lower Manhattan and on the Upper East Side.

Loehmann’s, founded 86 years ago in Brooklyn by Frieda Loehmann, has gained a renown over the years for its off-price designer merchandise and its kitschy communal dressing rooms. But for its new uptown store, the retailer — purchased last year by Istithmar, the investment company owned by Dubai’s ruling family — is courting an upscale clientele with an advertising campaign featuring a statuesque redhead wearing stacked heels and pushing a $900 Bugaboo stroller. “It’s an homage to the Upper West Side, which is full of carriages,” Loehmann’s vice president of advertising and creative, Ferdinando Forcellati, said. “Manhattan shoppers are much savvier than other shoppers. They really understand labels, and love to find great labels at great prices.”

For those customers, the new store also boasts both private and communal dressing rooms, and, like the Loehmann’s that opened 11 years ago in Chelsea, employs a full-time personal shopper, whose services are free to customers. Among the most sought-after pieces are Oscar de la Renta ball gowns, and separates from Italian designers such as Prada, said the personal shopper at the Upper West Side location, Madeline Ruiz, noting she is already fielding requests.

At the Ansonia, which is on Broadway between West 73rd and 74th Streets, Loehmann’s supplants a Gristedes supermarket on the building’s ground- and basement-level. Replacing the grocery aisles are wall-to-wall racks of deeply discounted apparel: A $1,200 navy blazer by Narciso Rodriguez is marked down to $400, while a $56 floral toddler sundress by Lilly Pulitzer sells for $35.

Loehmann’s is reportedly paying about $250 a square foot for the 37,000 square-foot space in the building, where The North Face, Sephora, and Commerce Bank are also located. The discount store is subletting the basement-level space from Gristedes, and leasing ground-floor space from Ansonia Associates, which purchased the building in 1978 and converted it to condominiums in 1990, according to managing partner of Ansonia Associates, Jesse Krasnow.

News of the building’s new tenant drew a mixed reaction from residents of the Ansonia. While some are happy to be rid of a supermarket, which they say attracted vermin and a glut of delivery truck traffic, others say they were hoping a luxury retailer would open up beneath the 103-year-old residence.

One resident, Michel Madie, said the space would have been ripe for a fashion specialty store such as Jeffrey New York. “We’re surrounded by multimillion-dollar condos, so I’m sure there’s a clientele for that,” he said.

Mr. Madie, a real estate broker who owns several units in the Ansonia, said a bargain retailer like Loehmann’s is “not the worst thing that could happen to the building — it’s better than a noodle shop — but it fits with a sinking boat, rather than a rising ship.”

But for a long time, the once-prestigious address was floundering, and only in recent years has it begun to revive itself. In the 1960s and 1970s, the Ansonia became a symbol of urban excess and decay during the latter half of the 20th century. Suffering from neglect, the building fell into disrepair and in decades past attracted as tenants a bathhouse and a “swingers” sex club.

A writer who chronicled the history of the Ansonia in his book, “The Sky’s the Limit: Passion and Property in Manhattan” (Little, Brown and Company, 2005), Steven Gaines, said Loehmann’s is an ideal anchor tenant for the ornate high-rise. “The building has always housed a collection of interesting people and things, and Loehmann’s is a great addition,” he said.

Mr. Gaines said that despite skyrocketing real estate values, the Upper West Side has always had more of its “mass-market appeal” than its cross-town counterpart, and that luxury retailers like Prada or Gucci wouldn’t suit the neighborhood.

The Upper West Side arrival brings the number of New York City Loehmann’s stores to four. In addition to the 60,000 square-foot space in Chelsea, the retailer has locations in Brooklyn’s Sheepshead Bay neighborhood and in the Riverdale section of the Bronx.