A symbolic ground-breaking at the Tisbury School Saturday morning marked a new chapter for the town school, which graduated its first class of eighth-graders more than 90 years ago.

With shiny commemorative shovels in hand, town officials and school committee members celebrated the long-awaited start of a comprehensive, $81 million renovation and addition approved by voters this year.

“This project is exciting and promising,” said principal John Custer, who graduated from the Tisbury School in 1984. “It’s something our community has worked towards for many, many years.”

The project is by far the largest of any kind that Tisbury has ever undertaken, town treasurer/collector Jon Snyder told the Gazette.

After the shovel ceremony, Mr. Custer led visitors on a tour of the temporary school, which opened for classes following Thanksgiving break. Nondescript from the street, the four modular buildings are all about what’s inside: everything needed to run a school for more than 250 children in kindergarten through eighth grade.

In the three classroom buildings, dubbed B, C and D, center hallways are lined with kid-height coat hooks, student artwork and recess-ready playthings: a stack of Hula Hoops here, a net of soccer balls there. On either side of each hallway, classrooms sport colorful rugs atop linoleum floors. Fish swim in a tank at the back of the science room.

In the media center/library, computer workstations share space with a carpet where young readers can curl up with real books.

Building A is half the size of the classroom buildings, Mr. Custer said, and houses the school’s administrative offices, nursing and counseling and a room for vocal and instrumental music.

The modular buildings will house the school for the next year and a half, if all goes to plan with the renovation and addition. The school committee and school building committee will meet jointly Dec. 13 at 4 p.m. on Zoom to give an update on the progress of the project.