In a move that could become a model for those seeking to satiate a parched Manhattan private school market, an Upper West Side nursery school is launching an expansion into the elementary and middle grades.

The Mandell School on 94th Street now serves 2- to 6-year-olds, but in coming years it intends to stretch to eighth grade. It is leasing an additional property on 96th Street and hiring new teachers and administrators. The first-ever kindergarten class will launch in September.

In a letter to applicants, the school’s director, Gabriella Rowe, said the expansion is Mandell’s response to the city’s hyper-competitive private school market. In the past eight to 10 years, she wrote, the race for kindergarten spots has grown so cutthroat that it is exacting a “devastating” toll across the city.

Early childhood centers “have developed an overlay of constant ex-missions preparation,” she said, and parents and teachers are resorting to thinking of 4-year-olds as “competitors” who must be “packaged.”

The only answer, she concluded, was to build more quality school spots.

Parents seem to be embracing the expansion. Ms. Rowe said she has received many kindergarten applications — “almost too much to handle,” she said — and two admissions consultants, Victoria Goldman, the co-author of the “Manhattan Family Guide to Private Schools and Selective Public Schools,” and Robin Aronow, the founder of the consulting firm School Search NYC, said they have clients who are applying.

Given the widespread sense that demand for kindergarten spots is at an all-time high in Manhattan, there have been surprisingly few attempts to add more.

When a new school, Claremont Preparatory School, opened in Lower Manhattan, administrators could not initially fill all the spots they planned to create. The school is now attracting more interest, but few others have stepped up to follow Claremont, whose creation cost $40 million in start-up alone. The problem, private school administrators say, is twofold: Real estate and reputation. Getting a facility has never been more expensive. Getting parents to spend thousands of dollars on a name and brand is perhaps an even bigger challenge.

Mandell’s approach appears to break both barriers. Ms. Rowe said the school is and always has been a for-profit business. That may make a new lease on 96th Street easier to finance.

Even more helpful is Mandell’s built-in leg up on the reputation problem. Known as one of the city’s “Baby Ivies,” Mandell is consistently a top choice for Upper West Side parents. Ms. Rowe said she receives between 10 and 15 applications for every spot she can offer.

Ms. Rowe said the school’s experience is indeed an advantage. But she said Mandell’s expansion should just be considered a starting point. To break the competitive culture, she said, other nursery schools will have to follow the school’s lead and expand.