The new Lower Manhattan academy that is working to have its name added to the list of elite private schools in the city, Claremont Preparatory, is preparing to open a new high school in 2009.

A new administrator with 10 years of experience running the high school at Dalton, Judith Sheridan, will run the new high school, which will be built near Claremont’s current location inside an abandoned bank headquarters blocks away from the Stock Exchange.

The school’s headmaster, Irwin Shlachter, said Ms. Sheridan was one of three applicants for the job who had ties to a brand-name New York City private school.

The announcement is a sign that Claremont, which early on struggled to fill all its spots, is enjoying a new period of growth.

Its trick: Rather than treating its lack of experience as a weakness, the school is spinning it as a selling point.

“You would think that, at a new school, you’re not going to get people with lots of experience who have already been in big schools,” Mr. Shlachter said. “But the truth is that it’s an opportunity for them to shape something and to kind of come up with their own version of what the high school should look like, and, you know, dream big.”

Ms. Sheridan said she is planning to make Claremont’s high school a truly 21st-century school, teaching students something she called “global fluency.” She described a possible lesson on the environment: Rather than discuss the lesson alone, students would log onto the Internet to learn it side by side with students an ocean away.

The unprecedented demand for schools as families flood Manhattan has made such dreaming worthwhile.

Ms. Sheridan, who currently directs a service at Columbia University that helps faculty and staff find school options for their children, said she has seen the demand firsthand.

An educational consultant who once had difficulty getting clients to consider Claremont, Emily Glickman, the president of Abacus Educational Consulting, said she has placed several happy families there this year.

“As the public school process has become more and more chaotic and uncertain, people are looking for any safe place to go to school,” Ms. Glickman said. “And even though a new school will not be a family’s first choice, it’s often a good choice.”

Ms. Sheridan said the opportunity to build a new school from scratch — from curriculum to technology to the way the day is scheduled — is a dream come true.

At established schools, she said, such changes would be difficult to instill.

“There’s a holding on to what is, rather than looking forward,” she said. “Very often it becomes a matter of negotiation. In this case, we start fresh.”

Claremont’s lower and middle schools are already attracting attention. A deputy mayor of the city, Kevin Sheekey, has visited Claremont and described the school as a model of Manhattan’s vibrant new downtown.

“They see us as a destination for Lower Manhattan,” Mr. Shlachter said of City Hall officials. “There’s a shortage of schools, and the public schools have not addressed the needs of the population, so they see us as meeting a need in the community.”