The Washington region is a hot zone of student achievement, with leading high schools offering a plethora of Advanced Placement and International Baccalaureate classes to prove that theirs is a rigorous path to college.

But next year, a public charter school will open in the nation’s capital that raises the concept of academic rigor to a new level. Seventh-graders will take Algebra I and Latin. AP courses will not be an option for high school students — they’ll be the heart of the curriculum.

To graduate, students will be required to complete at least eight AP courses and pass six exams.

The school, to be known as Basis DC, replicates a model developed in Arizona and represents a potential turning point for a charter sector in the District that has grown explosively in the past decade but yielded uneven results.

Its founders say the school will be a game-changer for a city struggling to raise the quality of educational offerings for poor children.

Skeptics question whether the intensely demanding approach can succeed in a city that is poorer and more diverse than the communities the charter operators have served.

“I’m all for high standards. I’m all for excellent curriculum. Kids should be pushed. But you have to recognize the population,” said Skip McKoy, a member of the D.C. Public Charter School Board.

McKoy, the only board member who voted against the opening of Basis when it was approved last month, said he thought that the charter operator “brushed aside” concerns about the ability of students behind grade level to succeed.

Olga Block, a Czech native and former college professor who founded Basis 13 years ago with her husband, economist Michael Block, said their schools can educate anyone who walks in the door.

“We know how to do this,” she said. “We’re very good at it.”

The District isn’t the Blocks’ only target. They indicated in their application that they plan to open two to four new schools a year across the country by 2016.

For the D.C. charter sector, the nation’s fastest-growing outside of New Orleans, Basis represents a new direction. D.C. charter schools educate nearly 29,000 students — about 40 percent of the city’s public school population — on 93 campuses at an annual cost of $400 million.

But with expansion have come concerns about quality. In the past two years, 11 charter schools have closed voluntarily or by order of the charter board, primarily because of academic or financial problems.

The overwhelming majority of D.C. charter schools were founded by local groups. Some board members say it is time to look for more organizations, such as Basis, with a track record of success outside the city.

The Basis formula offers austere, European-style rigor — eighth-graders must pass the University of Cambridge international benchmarking exam — without many of the usual extracurricular bells and whistles of U.S. high schools.

“I have a math program. I have a physics program. I have a calculus program. What is this about a music band?” Block told the Arizona Republic in 2006. She said her classrooms were for “workaholics.”

The charter board’s approval overrode the objections of its staff members and four consultants, who said Basis could not demonstrate how it would adapt its rigorous approach to the District, where it will be required by law, as it is in Arizona, to take all students on a first-come-first-served basis.

“The founding group could not satisfactorily explain how the school would meet the needs of low-performing, special education and English Learner students effectively, and seems not to grasp these challenges fully,” the consultants reported.

The Blocks will face vastly different demographics in the District, where public enrollment is nearly 80 percent African American, 12 percent Hispanic and 7 percent white. Last year, 54 percent of the 655 students in the flagship Tucson school were white, 21 percent Hispanic, and 19 percent Asian or Pacific Islander. Less than 4 percent were black.

While the Blocks claim success with students at every level of need, state figures show that just 10 of the 655 students in Tucson had special-education status. Basis does not track the number of students eligible for free or reduced-price lunch — a widely used index of household poverty — because it does not serve lunch. Basis officials said that the D.C. school will offer lunch.

The charter board staff report also cited concerns about how Basis plans to support students who are behind. The charter operators propose to outsource most remedial programs to nonprofit organizations. Reviewers also flagged abnormally high projected attrition: Of the 145 fifth-graders expected to enroll in 2012, 38 would remain Basis students by ninth grade, a retention rate of just over 25 percent.

Reviewers also questioned whether the two-week registration period Basis plans in October will give officials enough time to market the school throughout the city. By contrast, E.L. Haynes, a charter school in Northwest’s Petworth neighborhood, has a four-month window.

D.C. charter school blogger Mark Lerner, a member of the board of Washington Latin charter school in Northwest, wrote last month that Basis “blatantly markets itself to elite students” and is “a direct affront to the civil rights struggle so many have fought over school choice for underprivileged children.”

Block said she regards income and ethnicity as “absolutely irrelevant.” She said no one has been turned away from her schools in 13 years of operation.

Basis is seeking a central location convenient to mass transit, possibly near the 14th or 16th street corridors in Northwest. “We will make sure that every ward knows about the school,” Block said. In its first year, Basis is expected to cost $5 million in public funding, starting with students in grades 5 to 9.

Most charter board members said that the Basis record in Tucson, which includes a Top 10 ranking in Newsweek’s annual high school survey for the past five years and annual standardized test scores that exceed statewide averages, has earned the school a chance in the District.

Board member Will Marshall said the board wants to take more chances in its selection of charter operators and to broaden options.

“We are at a stage where we need to be bolder about innovation,” said Marshall, president of the Progressive Policy Institute, a Democratic think tank. “My own sense is that I’d rather err on the side of taking a risk and getting a really superior school than one that merely looks like it’s possibly a good school but that doesn’t excite.”

Board Chairman Brian Jones said the approval of Basis is contingent on how the school demonstrates it will reach out to diverse sectors of the city. Jones, who was a general counsel at the U.S. Education Department under President George W. Bush, disputed critics who say the board’s action showed a lack of commitment to poor children.

“As a school model with that kind of rigor, Basis at the end of the day may not be for every family in the District,” Jones said. “But that’s part of the genius of the charter school model. There’s a diversity of models — the whole notion of letting a thousand academic flowers bloom.”

Mary Siddall, a public school mother who is helping to launch Basis DC, said she learned of the school through Clint Bolick, a prominent conservative legal activist who serves on the Basis Arizona board.

Siddall said Basis DC would serve diverse students.

“I’m not going to put my name on anything that’s going to be a school for rich white people,” she said.