The best thing about completion of a nearly three-year construction project at South Portland High School is that all the learning spaces can now be used as originally designed, according to Principal Ryan Caron.

No longer will video classes be held on the stage in the auditorium; no longer will teachers have to share space or switch classrooms over and over again. And, Mountain View Road is once again open to two-way traffic.

On Sunday, the community of South Portland celebrated completion of the 33-month, $47 million addition and renovation project with a ribbon-cutting ceremony and open house.

More than 100 people turned out to get their first look at the fully operational and updated high school before students returned on Monday.

Caron said Monday went “very well (with) lots of positive energy from both students and staff,” although he said it would take a while before they get used to the new traffic patterns, including the new bus loop and main entrance off Mountain View.

“We did it,” outgoing Superintendent of Schools Suzanne Godin said following the ribbon cutting on Jan. 4. She said the key items the new building addresses include the creation of “flexible, modern classrooms” that reflect how learning is accomplished in the 21st century.

Other important factors, Godin said, are that the high school is now 100 percent handicapped accessible and fully secure, with anyone wanting to enter the building after 7:30 a.m. required to be buzzed in by main office staff at the front entrance.

She said the project consisted of about 200,000 square feet of new space, which was opened to students and the public last year. The addition includes the new main office, the learning commons or library, the cafeteria, a lecture hall and a gym.

The renovation consisted mostly of gutting and updating much of the classroom space, according to Godin, as well as construction of the new bus loop and main entrance.

The high school project was funded with a local bond, which was approved by voters in 2010. That bond was for $41.5 million. Godin said the remaining $5.5 million came from a variety of sources, including energy credits and money set aside from the city budget.

Ground was officially broken in 2012 and a ribbon-cutting ceremony was also held in January 2014 to celebrate the opening of a big portion of the project- the new addition.

During Sunday’s ceremony, Richard Matthews, chairman of the Board of Education, called the construction project “a long and winding road toward a brighter path to the future for our students.”

Mayor Linda Cohen said the city’s students “deserve first-class facilities and technology” and that teachers deserve “the tools they need to teach” in the 21st century.

According to a representative from PC Construction, the general contractor, the project took about 200,000 man hours to complete. He said the school went through a “total transformation” that has “put South Portland on the map.”

In her public comments on Sunday, Godin said, “I am excited to open a complete South Portland High School. Walk around and enjoy.”

When asked if there was anything in particular about the new school they would have liked when they were students, recent alumnae Ali Schwartz and Emily Baker said “All of it.” But they were most impressed with the learning commons and lecture hall.

Schwartz, who graduated in 2012 and is now a student at the University of New Hampshire, called the high school project “really exciting and disorienting. It feels like a totally different school. It’s really nice.”

Baker graduated in 2014 and is in the media studies program at the University of Southern Maine. She came out to see the new school and visit with her former teachers.

“They love (the new school). They’re very happy and they deserve it,” she said.

Jacci Morin, a 1987 graduate of South Portland High School, was there Sunday with her two daughters and said that nothing looked familiar from when she attended the school 28 years ago.

“It’s beautiful and it turned out great,” Morin said of the addition and renovation project.

Her daughter, Rachel, will be a freshman in the fall, while her younger daughter will get to the high school in another two years.

Former Principal Jeanne Crocker said the completed school building is “every dream fulfilled,” adding, “I have goose bumps, I am so excited for the students.”

She said the construction project addressed a variety of deficiencies, from lack of space to infrastructure needs, as well as student and staff health and safety and said that it would serve the community for the next 50 to 60 years.

Resident Patty Young also attended Sunday’s event with her two sons, one of whom is a sophomore. She called the construction project “long overdue.”

“For me this is a much better environment (for my kids) to learn. It’s just so nice to have something fresh. The old school was worn down and some of it was straight out of the 1960s,” she said.

For Caron, the end of the construction project means he can now focus on moving forward with educational initiatives that were put on hold while the school was in disarray.

“This is the school the community deserves,” he said. “I hope they’ll be impressed with what they got and will be proud of the kids graduating every spring.”

South Portland Superintendent of Schools Suzanne Godin, right, and Ralph Baxter Jr., chairman of the high school building committee, team up to cut the ribbon and officially open the newly renovated high school on Sunday.More than 100 people attended Sunday’s ribbon cutting ceremony during an open house at the South Portland High School, which recently underwent a $47 million addition and renovation.South Portland Mayor Linda Cohen addresses the crowd assembled for the ribbon-cutting ceremony and official opening of the newly renovated building.At right, Randy Martin, a South Portland parent and member of the high school building committee, explains some of the changes in the school’s layout to June Harbison.