The fledgling Independence Mission Schools network of Catholic elementary schools is used to moving fast.

It sprang into action two years ago to save 14 parish schools in low-income neighborhoods when the Archdiocese of Philadelphia announced plans to close them.

And when the cash-strapped Philadelphia School District listed the shuttered Harrison Elementary School in North Philadelphia for a quick sale last fall, the network scrambled to raise $1.36 million to buy it to replace the nearby St. Malachy school.

"This has never happened before," said Al Cavalli, president of the Mission Schools network.

When the network took over the former parish schools from the archdiocese last summer, it knew it eventually would need to find new facilities for St. Malachy and a few others, said developer Michael F. Young, a member of the Mission Schools board. But the network had no immediate plans to do so.

"A year ago, we weren't sitting here saying we need a building at this location," said Joseph Stapleton, a lawyer who is also on the board. "It came on the radar screen, and we jumped on it.

"We have to have a very nimble board."

The School Reform Commission approved the network's bid in March. The sale, which was finalized June 10, will allow one of the city's oldest Catholic schools to move into expansive, refurbished quarters with playing fields in September 2015. The total price tag is expected to be $5 million.

"People are excited to see what's going to happen there," Teresa Richardson, St. Malachy's principal, said Friday. "More space means more programming."

The K-8 school has 182 students. The building is so cramped there's space for only a single class per grade and no room for a prekindergarten program.

A tiny office for the secretary was built on the stage of a large room that serves triple duty as cafeteria, gym, and auditorium. The principal's office is stage left.

There's a little playground for the youngest students, but the older ones have recess in the parking lot. And the walls of the 1890s building are so thick, getting a WiFi signal is difficult.

Fast-forward to fall 2015, when St. Malachy's relocates to the former Harrison Elementary School a block and a half away. There will be room for two classes per grade, space for a preschool program and, the prospect that enrollment could swell to 550 to 600.

"If we are going to run these schools going forward, we're going to want a scale that is going to allow us to invest in the buildings, the technology, and in the teaching staff," Young said. "And that drives us to operate larger schools."

After the move, St. Malachy will be able to hold assemblies in the 378-seat auditorium. The facility, built in the 1920s, also boasts a gym. And the school will have a cafeteria with a small kitchen.

The Mission board envisions bright, refurbished classrooms with 21st-century technology. And the network's plans call for a green makeover of the 2.6-acre city block, now the site of a three-story building with asphalt surrounded by a 10-foot fence.

"We're going to make playing fields out of it," Young said. "We're going to put basketball courts in there. You're going to have some green areas outside . . .. This will be transformative in this North Philadelphia neighborhood."

Young, who founded Young Capital & Classic Management Inc., which has several large apartment complexes in Northwest Philadelphia, said the former Harrison school was especially attractive because it was structurally sound.

The purchase is the latest development in the two-year history of the Independence Mission Schools.

The concept is based on the successful model of the St. Martin de Porres School in North Philadelphia, which increased enrollment, stabilized finances, and added programs after it became independent of the archdiocese three years ago.

In July, Archbishop Charles J. Chaput designated the former parish schools in low-income neighborhoods as Catholic "mission schools" that would be operated by the independent network.

Chaput said the change would ensure that schools would continue to provide a Catholic education to children in the city's neediest neighborhoods. Nearly two-thirds of the students are not Catholic.

Except for St. Cyril of Alexandria in East Lansdowne, the schools are in Philadelphia. Mary, Mother of Peace Area Catholic School in Southwest Philadelphia will join the network July 1 under its former name, St. Barnabas.

The schools are now run by the independent board and network's small staff instead of by pastors of the parishes where the schools are situated.

"The principals," Cavalli said, "report directly to me."

However, the schools remain Catholic.

"That is part of our agreement with the archdiocese," Stapleton said. "But we serve children of all faiths."

Each mission school also has its own board involved in running the school.

The network has taken over marketing and recruitment, developed websites and brochures, and handles finances and purchasing for the schools.

And instead of individual schools' setting their own tuition, the Mission Schools network has adopted a rate of $4,000 but considers families' ability to pay.

With aid from the Children's Scholarship Fund Philadelphia and others, enrollment at the schools has grown 7.5 percent.

"When you look at it over an 18-month span, we're going to have taken these schools from about 3,800 children to close to 5,000," said Anne McGoldrick, the network's chief financial officer.

Under the independent board, the Mission Schools have found support from those who have not typically contributed to Catholic education.

"We have seen . . . new donors invest in the schools as part of a civic solution," McGoldrick said.

The fund-raising, support from members of the Mission Schools board and St. Malachy's board, and a short-term bridge loan enabled the network to buy the Harrison School, Young said.

"We still have to raise $3.5 million to really affect the renovations and open the school for the 2015-16 school year," Young said.

"Although we believe we have identified some sources of money, we have a long way to go."