The new four-floor high school will accommodate years seven to twelve, with the old one remaining in use while the new one was built.

The second phase of the project involved demolishing the old high school and building the middle school, with renovation work on Field House taking place over three summer holidays.

The school’s gym and swimming pool were renovated and new playing fields were added.

Heating and cooling of the new buildings will be provided solely by 283 geothermal wells.

Bryan Northrop, Skanska USA’s executive vice president, said: “Working in tandem with the Town of Belmont to ensure all goals were met, we utilised our extensive experience in building educational facilities to successfully execute this substantial renovation on time and with minor disruption to the students’ and faculty’s day-to-day operations.

“The fossil fuel-free facility will meet LEED Gold standards and sets the benchmark for sustainable school construction in Massachusetts.”