$73 million school in Roxbury is the first newly constructed BPS school building in 15 years

City and school officials toured the school Wednesday.Pat Greenhouse/Globe Staff

Natural light filters through the four-story glass and steel building. There are state-of-the-art science labs, a computer center, and a rooftop garden for botany lessons. Even the boiler room can double as a real-world teaching lab for physics.

The $73 million Dearborn 6-12 STEM/Early College Academy — the first newly constructed school for the Boston system in 15 years — is a far cry from the century-old building it replaced in the heart of Roxbury, where young Irish immigrants once learned how to sew, iron clothes, make beds, and clean bathtubs as future maids for the wealthy in the Back Bay and Beacon Hill.

Mayor Martin J. Walsh, who will hold a ribbon-cutting Thursday afternoon, hopes the school will serve as an inspiring symbol of his pledge to spend $1 billion over 10 years to overhaul the city’s school buildings, roughly half of which were erected before World War II.

And those at the Dearborn, which has struggled academically for many years, hope the new building will represent a fresh start and instill a new sense of confidence and self-worth in their students, many of whom have been touched by violence or endured difficult journeys from their homelands for a new life and greater opportunity in the United States.

The Dearborn and its community partners had pushed for the new building for more than a decade.

“This is incredible,” said Natalina Mendes, a sixth-grade teacher, during a break from the first day of training seminars on Wednesday. “Our kids deserve this, and [this building] says they are worth this. . . . This is what we fought for.”

The mechanical room.Pat Greenhouse/Globe Staff

The much-anticipated building has long been the missing piece in the Dearborn’s effort to turn around academic performance, many of the school’s supporters contend.

The state declared the Dearborn “underperforming” in 2010 because of persistently low test scores.

It narrowly averted a state takeover in 2014. The school system hashed out a deal with state education leaders to bring in an outside partner — the Boston Plan for Excellence — to run the school, starting in 2015.

Yet scores remain low on state tests, even in the subjects included in the school’s name —

math and science — raising concerns about state receivership again.

Just 12 percent of the Dearborn’s middle-school students met or exceeded expectations on the math exams, and only 2 percent did in science, according to the most recent MCAS scores in 2017. Its 10th-graders fared better, with 51 percent scoring proficient or higher in math and 34 percent doing so in science.

After describing the features of the gymnasium, Patrick Brophy, the city's chief of operations, went for a few baskets.Pat Greenhouse/Globe Staff

The Dearborn educates some of the most challenging students in the system. Most live in households receiving government assistance, while many are newly arrived immigrants, typically from Cape Verde. Some 43 percent do not speak English fluently.

The challenge will grow greater over the next few years as enrollment expands from 350 last year to 600. About 480 students are currently on the rosters.

Dearborn staff said Wednesday that they are keenly aware it will take more than a building to elevate performance.

“Steel and glass doesn’t make a new school, [but] it gives us opportunity,” said Shelley Olson, principal of the middle-school program, noting the quality of instruction and the sense of community that staff and students build will move the school out of state monitoring.

A viewed from inside the mechanical room.Pat Greenhouse/Globe Staff

“Our students deserve to have the same level of education as every student in the city, the state, and the country,” she added.

Students will need only to look out many of the windows, which offer panoramic views of the city’s skyline, including the booming Seaport and the Longwood medical area, to see what job opportunities the city can provide.

The school plans to initially offer three career pathways — computer programming, engineering, and graphic design — and is looking to develop one for health careers.

The 128,000-square-foot building itself should foster a sense of collaboration and professionalism. Students can gather on lime green or yellow couches or stools in the learning commons in the hallways for robotic experiments and other lessons. Classrooms feature computer-interactive white boards and glass walls, allowing passersby in the hallways to peer in.

Two of the statues that were on the old school now graced a courtyard.Pat Greenhouse/Globe Staff

Wi-Fi is available throughout the building.

Students also can use three-dimensional printers to design objects and can use special laser cutters to create items in a “maker space” or a fabrication lab, a 21st-century twist on the old-school wood shop.

But the Greater Boston Interfaith Organization, one of the groups that pushed the city a decade ago to construct the school, is raising concern that the Dearborn doesn’t have enough money for key positions, such as a full-time STEM director and IT director. The school began advertising this month for a fabrication lab director and only hired a career pathway director this week.

Consequently, the school doesn’t have a fully developed STEM curriculum.

“It’s really an abomination to have this amazing STEM building and not have adequate staffing,” said the Rev. Burns Stanfield, president of the interfaith organization. “It really sets kids up in this neighborhood for failure.”

The school system defended its commitment to the Dearborn.

“Boston Public Schools is currently working with Boston Plan for Excellence on developing a strengthened STEM curriculum for Dearborn STEM Academy,” the school system said in a statement. “BPS is committed to supporting the development of the STEM curriculum, which includes funding a consultant and providing other items of support.”

It was the Roxbury Presbyterian Church, under the leadership of the Rev. Hermon Hamilton a decade ago, that spearheaded an effort to save the Dearborn, which the school system was considering closing because of low enrollment and poor student achievement. But the church saw the school as a potentially powerful catalyst to help better prepare students in the neighborhoods and initially pushed for a renovation and later a new structure.

Former mayor Thomas M. Menino became a supporter, and the project received state approval for funding in March 2014, three months after Walsh took office. The Massachusetts School Building Authority covered about $36 million of the cost of the project.

By that fall, the Dearborn vacated the site, moving into the fourth floor of the Jeremiah Burke High School in Dorchester. Occupying a single floor came with tradeoffs, such as not having space to offer arts programming or AP classes, although it offered its first calculus class last year.

In the digital lab, senior Elias Arroyave, 18, told computer science teacher Jon LoPorto what he figured out about the 3D printer.Pat Greenhouse/Globe Staff

One student, Elias Arroyave, 18, a senior, swung by the school Wednesday, to help out his teacher and tried out a 3-D printer.

He said he is excited to spend his last year in the new building after the temporary location at the Burke and the previous rundown Dearborn building.

“They have been amping up this school for so long,” he said. “The school was built for students. That helps us gain more confidence . . . toward learning and trying to graduate.”

Josh Fidalgo, dean of students, said he wishes a school such as the Dearborn had existed when he grew up in Boston. He went to schools in the suburbs through Metco.

“It’s amazing that kids don’t have to go out of the city to get what we have right here,” he said.

Glass panels reflected the neighborhood at the new Dearborn 6-12 Stem/Early College Academy in Roxbury.Pat Greenhouse/Globe Staff