Judy O'Brien, the librarian at two schools in the building the city has proposed for a new charter school, speaks against the co-location plan. (Video below.)

Tensions ran high at the city’s first charter school co-location hearing of the year Tuesday night as advocates and opponents of the city’s plan to open a new Success Academy school in Brownstone Brooklyn packed the proposed site.

Officials from the Department of Education and SUNY’s Charter School Institute defended plans to add Brooklyn’s third Success Charter Network school to a four-story Cobble Hill building that already houses three other schools, saying that the building has space for all four schools.

The charter school would admit 80 to 90 kindergarten and first-grade students in 2012 and grow by one grade per year until becoming a kindergarten through 5th-grade school.

According to the DOE official in charge of new schools, Deputy Chancellor Marc Sternberg, enrollment at the charter school would ultimately increase to somewhere between 500 and 640 students, and the total number of students in the building would climb to 1,400 or more.

“That would bring the school to 108 percent occupancy,” he said.

In response, a member of the sometimes-rowdy audience who said he was a teacher and was later ejected by police after he shouted inappropriate words called out, “Where do you want the kids to learn, the bathrooms? Where do the other 8 percent go to class?”

Sternberg acknowledged that the charter school would grow too large for the building in 2016, when it would add fifth grade for the first time. He said the department had plans for the fifth grade to open at a separate site but emphasized that the Baltic Street building “is being contemplated as a long-term siting” for Cobble Hill Success. A second site could allow the school to grow should it choose to apply for an expanded charter to serve middle school grades.

“That is not unusual,” Sternberg said of the plan.

Educators and community leaders lobbed questions about the complications that co-locations raise and questioned whether the school would be better off in another Brooklyn district.

Members of District 15’s Community Education Council who led the first half of the meeting pressed the SUNY Charter Institute’s staff attorney, Tom Franta, to explain whether the school, which was approved for District 13, could legally open in District 15 instead as is now planned. Franta said it would be acceptable for the school to change locations within the borough without gaining new approval from SUNY.

But he said the school would need to seek approval from SUNY if it choses to eliminate the “at-risk design factors” in its charter, which features a lottery system that privileges low-income students and English Language Learners from Districts 13 and 14. The school has indicated to SUNY that it would seek those changes to its admissions system “at a later date,” Franta said.

Opposition to the co-location came throughout the four-hour-long meeting from teachers and families that attend the two secondary schools that inhabit the building, regular activists, and District 15 CEC members. The building also houses a small school for students with severe disabilities.

“I’m actually very much in favor of charter schools,” said Eddie Rodriguez, a member of CEC 15. “The charter that was authorized was to serve high-needs kids. Placing this particular charter here will not serve that need.”

Sternberg disputed the claim, voiced throughout the evening, that District 15 does not have high-needs students for the charter school to serve.

“We are geographically located near Red Hook; we are geographically located near a set of housing projects,” he said. “We believe this charter school has a record and a real commitment of serving high needs.”

A Success Charter Network school that opened this year in another neighborhood with many middle-class families and high-performing schools, the Upper West Side, 40 percent of students qualify for free or reduced-price lunches.

Sternberg emphasized that District 15 students will have preference to gain seats at the new charter school, even though its current charter does not include this focus in its admissions process.

“This is going to be a district school of choice. It will attract families from across the district,” he said. “Upper West Side Success has 96 percent of families from District 3. Based on that track record we are quite certain that this organization will recruit District 15 and serve District 15.”

Teachers and families from the two schools said they are afraid splitting shared spaces three ways would squeeze instructional and lunch time.

“Our gym, our library, our cafeteria — these are spaces that within the building are already maxed out,” said Clare Daley, the technology teacher at the School for Global Studies, which jumped from an F report card grade to a B this year after low-performance brought federal “transformation” funds. “We are looking forward to expanding enrollment. … With this progress, why then would the DOE want to put another school in this building?”

Sternberg promised that the co-location would not negatively impact programs at the schools, which together offer special instruction in music, culinary arts, and creative writing.

Several students commended the small schools’ more intimate tone during the public comments portion of the hearing.

“Do you guys ever double check?” School for International Studies sophomore Alex Alvarez asked DOE officials. “Do you understand how hard it is to have a classroom of 30-35 students?”

Before the hearing, a half-dozen parents who said they live in District 15 rallied in the rain outside the Baltic Street building to support the charter school plan.

Jenna Sternbach, who lives nearby and has three children under the age of 5, said she prefers the creation of a Success Academy to the alternative proposal that has been floated by some community members in recent weeks, which would have an early childhood center open in the building to alleviate some of the demand for kindergarten options in the school.

“Success isn’t just a K through 1 option,” she said. “You’re not going to be scrambling to find a good middle school. You’re secure from kindergarten through eighth.”