When Luis Soto drops his son and daughter off at Pyne Poynt Middle School, 13-year-old Christopher goes through the front door dressed in a red polo shirt and Alianna, 10, walks through the side door to greet other students in Mastery blue.

"They both seem to come home happy," Soto said two weeks into classes while waiting for them outside before dismissal.

Mastery Charter Schools' newly opened North Camden Elementary School, a district-charter hybrid known as a "Renaissance" school, is renting space inside Pyne Poynt Middle this year. Mastery's K-5 classrooms are mostly on the first floor and Pyne Poynt's seventh- and eighth-grade classrooms are mostly on the second. The schools have separate staircases but share the gym, cafeteria, and library space.

Despite criticism that Camden's first co-location could become a physical embodiment of "haves" and "have-nots," the hallways look nearly identical, classrooms appear similarly stocked, and administrators in both schools say they are working together to prevent any feelings of segregation. That's not to say tensions couldn't arise, given that Pyne Poynt will be phased out in coming years and potentially yield the building to Mastery.

"The building we share cannot be looked at as a separate space for either school," said Pyne Poynt principal Tyrone Richards. "This is a shared building where we have common facilities. Both leadership teams are working together to ensure a successful educational program for all children."

Camden's first co-location has prompted complaints from some parents and community members. The arrangement also piqued the interest of the newly appointed president of the National Education Association, the nation's largest teachers' union. Lily Eskelsen Garcia announced that she would visit the school Friday.

Richards, a veteran principal in the district, born and raised in Camden, returned to Pyne Poynt this school year. He was principal in 2006.

He replaced Brian Medley who had appealed to Superintendent Paymon Rouhanifard to combine two traditional public schools instead of going through with the shared location with Mastery.

Mastery will pay $70,000 a year in rent to the district for the use of Pyne Poynt, money the district said may go to college scholarships for district students. Mastery also shares custodial, security, and maintenance staff with Pyne Poynt. Both use Aramark food services.

The co-occupancy lease maps out which parts of the building Mastery, which has 300 students, and Pyne Poynt, which has 185, can occupy, and schedules individual times for gym and cafeteria use. The lease goes for two years and can be renewed.

"We've collaborated very effectively," said Mastery principal Brandon Cummings. "We have a standing meeting every week to get the pulse of what's happening, and we're very respectful to each other."

Cummings said Mastery sent a cake over to the Pyne Poynt side on the first day and Pyne Poynt set up a bulletin board welcoming Mastery. When a water cooler overheated, prompting an unexpected fire alarm, both schools evacuated in less than three minutes and received praise from the fire chief.

There are plans for shared professional development sessions and potential reading mentorships between the older Pyne Poynt students and the younger Mastery students.

Mastery chief operating officer Joe Ferguson said the nonprofit was open to remaining at Pyne Poynt once the school phases out. Pyne Poynt, one of the lowest-performing schools in the district, did not take on a new sixth-grade class this year.

The arrangement initially made Pyne Poynt mother Melissa Rodriguez, whose son is in seventh grade, a bit nervous.

"It's not that big of a school," she said. "But it's only the second week. I think if we were to give it two months and then see how it's going, the kids are more focused on making friends right now."

Co-locations are common in New York City and Los Angeles.

Zakiyah Ansari, advocacy director for the Alliance for Quality Education in New York, said they have caused divisions.

"You had things that needed to be repaired," she said, "and a new school comes in with everything you were asking for. Students were greeted with 'Do Not Enter' signs in space that once upon a time they were able to go to. . . . What does that say to the very children who often live in the same communities? What message does that send to them about their worthiness?"

There are no blatant differences in the spaces right now. Mastery spent $750,000 on start-up costs for both North Camden Middle School and at a second location, at the former Washington School, where 100 K-2 students have enrolled.

The funds paid for bright paint on the walls, new furniture, routers to connect the Camden school to other Mastery schools in Philadelphia and laptops.

Pyne Poynt will get four laptop carts and additional smartboards, district spokesman Brendan Lowe said. Some classrooms still have chalkboards and older equipment.

Both sections of the building have new college banners on the walls.

Sharing a building doesn't affect student achievement, says Marcus Winters, a fellow at the Manhattan Institute, a conservative-leaning think tank, who studied test scores of New York City students before and after co-location.

"That's not to say there aren't challenges that come about," he said, "but whatever those challenges are, they don't seem to have an impact on what parents and policymakers care about most - how much learning is going on in a school."

Pyne Poynt, built in the late 1950s, replaced Clara S. Burrough Junior High, which Joyce Carter, now 72, attended. The ninth-generation Camden resident said that even if the hallways look the same, the writing is on the walls.

"Nothing should be turned over to Mastery or anybody else," Carter said. "That's public land, a public school, and it's wrong they went up there and passed legislation making it OK." A recent bill passed in the legislature allowed Renaissance schools to use temporary facilities.

Sol Angel Rivera has taught at Pyne Poynt for 33 years. She attended the school and was teaching while current principal Richards was a student.

She said sharing the space has been "fine," though she had to move from the first-floor classroom she'd had for 15 years to one on the second floor. She was pleasantly surprised when a Mastery teacher helped her set up her social-studies classroom.

"Every year there are new challenges," she said. "This is one of them, but basically I just go along with the program. Whatever comes, you adjust."