SALEM — The Granite State Arts Academy, an arts-based charter school in Salem, was recently granted unconditional renewal by the state to continue operating for the next five years. Its leaders say the school’s model has been hugely successful, enrollment is growing and programs are expanding.

In April, the state Board of Education approved the school’s first five-year renewal since its founding in 2014.

“The first renewal is a bit nerve-wracking,” Head of School Tony Polito said.

Many charter schools have to go through a rigorous process of meeting conditions and repeat reviews, but school founder Don Erdbrink said they were relieved when the board unconditionally granted its renewal after school officials answered all its questions.

Drew Cline, the chair of the Board of Education, said the review of GSAA went smoothly in part because whenever school administrators identified an issue they appeared to proactively develop a plan to address it. He said some of the things that stood out to him included how the school sought out parent involvement and was responsive to student needs.

“That was very impressive to us,” Cline said.

During the review process, the board interviewed students and parents. He said one of the complaints a student had was that they were spending too much time away from school. Cline said that’s not something they hear often.

In an emailed statement, Department of Education Commissioner Frank Edelblut said GSAA is doing a “fantastic job” by giving students a chance to build their ideal education.

“There are many paths to bright futures, and charter schools like Granite State Arts Academy are increasingly valuable pieces of New Hampshire’s public school system,” Edelblut said.

Erdbrink estimates the school’s enrollment grew from 53 students in its first year to 108 students in the second year, then 115 in the third year.

The school moved from a 12,000-square-foot building in Derry to a 19,500-square-foot space at 19 Keewaydin Drive in Salem in the fall of 2016, ahead of its third school year, which was followed by a drop in enrollment.

“We lost some kids because of the move,” Erdbrink said.

Enrollment reached a peak of about 135 in its fourth year, Erdbrink estimates. This school year had an average enrollment of about 120 to 130 students, he said, and they are projecting 135 to 140 students to be enrolled by the fall.

Erdbrink said the school has won New Hampshire Educational Theatre Guild awards, a teacher was nominated for educator of the year and they’ve seen students get accepted to good colleges across the country.

“Though only five years old we have had students accepted to Emerson, Berklee, Harvard, Maine College of Art, Mass College of Art and Oklahoma City University just to name a few,” Erdbrink said.

He said Oklahoma City University has a major dance program that supplies many of Broadway’s dance talent.

Junior Kayleigh MacFarland, 16, has sung the National Anthem for five Celtics games at TD Garden, and other major sporting events. Another student, Alexis Clark, 19, of Atkinson, was selected to represent New Hampshire in the U.S. All-National Choir, which is comprised of one student from all 50 states plus Washington, D.C., and Puerto Rico.

But not all students who graduate from GSAA go on to pursue a concentration in the arts.

“We’re not just producing musicians and artists, we’re producing, I like to say, out-of-the-box thinkers too,” Erdbrink said.

One student, who distinguished himself as a drummer while at GSAA, got accepted into Stanford University to study robotics and embedded technologies. Another senior will be going to the University of New Hampshire’s pre-med program.

Polito said that’s a reflection of how, even as a school focused on the arts, they still take regular academics seriously. The trick is how they integrate subjects like visual arts with science and math or video production with Spanish.

Students can take up to eight arts courses over the course of four years in the school, Erdbrink said, and many of those classes weave into one another. Sewing class produces 2D visual art, and also costumes for the school’s multiple theatrical productions over the school year. Recording studios are also wired to the school’s 140-seat black box theater space.

“(The theater) was probably the largest single expenditure,” Erdbrink said of the renovation costs.

He said the school used a $600,000 federal grant to fit up the first school location and help with the move. That was also supplemented by donations and volunteer hours.

Erdbrink said the school enjoys intimate class sizes of 10 to 15 students, and its charter aims to keep those classes under 20 students. The school also requires a total of 26 credits to graduate, Erdbrink said, which is higher than the minimum 20 required by the state.

Polito said the school’s academic performance has been growing stronger. In the past three years, its students averaged SAT scores of 930 to 940, he estimated. This school year, the combined average SAT score is 1013 (530 for English, 483 for math).

Polito said they are looking into adding a number of new programs, such as photography and sculpture and rock ensemble.

“We certainly want to expand the visual arts,” Polito said.

Polito also wants to expand the existing video and film programs. Rock ensemble already has 18 interested students lined up, Erdbrink said. He said it will be a way to modernize the school’s music program, with live rock shows out in the community, while still introducing students to classical music.

One idea is to have the New Hampshire Philharmonic, currently based at Salem High School, to come to the school for small shows and to potentially provide students with internships, Polito said.