DORCHESTER — A large image of a labyrinth on the floor surrounded by open space is common in medieval cathedrals, but it is not usually found in a high school. Yet, Boston College High School has added just that.

“We built it with the idea with it being almost like a sacred space,” president William J. Kemeza said about the central commons of the new wing, which features a labyrinth that is an exact copy of the well-known Chartres Cathedral labyrinth in France. It is the same size as the original and also oriented toward Jerusalem. Around the outer edge are the words “Ad Majorem Dei Gloriam” — “For the greater glory of God” — the motto of the Society of Jesus.

The students at BC High, an all male Catholic school in Dorchester, have tried walking the labyrinth, just as medieval travelers would before a pilgrimage, as part of a meditative, prayerful journey that was symbolic of life’s journey, Kemeza said.

“It really represents a Renaissance of the school itself,” he added. A balcony overlooks the labyrinth and has a view of the school’s new cafeteria, computer lab and classrooms. The facade of one of the five existing buildings has become an interior wall.

The opening ceremony on Feb. 28 began with a student ushering all to the central commons by piping an Irish song. A more formal ceremony with the blessing of the cornerstone will take place on April 14.

The school spent $22 million for renovations and the new wing, which connects all five buildings. The wing includes a science center, 18 classrooms, offices for teachers and counselors, a campus ministry area and shiny red lockers.

The update comes after years of delaying small repairs.

“We had been deferring maintenance on the school for a while,” said Kemeza who served as the school’s principal for many years.

The school administrators looked at the needs of students and built a new cafeteria with large windows that face Dorchester Bay. The previous cafeteria seated about 300 students and with an enrollment of about 1,300, four lunch periods were needed. The first started at 10:15 a.m. The new cafeteria seats 700 and will allow for two lunch periods, he said.

The school also expanded the already elaborate campus ministry program, Kemeza said. The program runs retreats on all levels and helps students fulfill their required community service — seniors have 150 hours alone. The office also places seniors in jobs at agencies, where they spend most of every day for six weeks of the school year.

“They come back and do reflection with us on a regular basis in small groups, reflecting on the connection with the gospel,” he said.

All of the classrooms are equipped with boxes that contain a DVD player, CD player and control the projector — all of which can be controlled by the teachers’ school-issued laptops. The whole school is wireless Internet accessible, which means teachers can take attendance and send it to the office, almost immediately, said Justin C. Holmes, director of communications for the school.

With all the changes, BC High is not expanding enrollment but has been dropping class size and giving teachers, who have four classes rather than the traditional five, more free time.

“This just eases things for us,” said Kemeza. “At least half the day, our teachers are available for one-on-one work with students, tutoring, etc., so that meant we needed a lot more space, a lot more rooms.”

In the past, the classroom had to be cleared, the board had to be washed, and students and faculty had to be evacuated for the next group to come in.

“Now a teacher can grab a student after class and say, ‘You know, I really liked that question,’” said Holmes.

Despite the changes, Kemeza said, he wants to keep the school like a “mini college campus.” When students have free time between classes, they are allowed to use facilities like the computer lab and library.

“The kids get to know how to use their time well,” he said.

The school has a “strong faith and commitment to forming leaders for the Church,” he added.

“We’re full of hope and faith about the future of the Church,” he continued. “This is such a strong sign for a Church institution to be building in the city.”

Students have been overwhelmed by the changes, Holmes said. They enjoy the fact that having all the existing buildings connected makes it easier to get to class, especially during the cold winter months when they previously needed to grab their jackets before heading outside to get to a different building.

Kemeza said the students are “awestruck” by the changes and already have plans for using the new space, especially the common ground area. In the first week the new wing opened, two groups of students had bake sales for charities. One was a doughnut sale for Rural Water Ventures, an organization that digs wells in Central America. It was started by a BC High alumnus, Bill McQueeney, who graduated in 1952, he said.

The addition has prompted faculty to find new ways to approach teaching as well. Both faculty and students have plans for receptions, gatherings and prayer services, he said.