ORANGE — Demolition of Dexter Park Innovation School began on Monday, starting the home stretch of a renovation project that has been in the works for at least six years.

The brick school, built in the early 1950s, will be replaced by a wildflower meadow and retention pond for drainage for the renovated adjacent Fisher Hill Elementary School, which is set to open to students in kindergarten through sixth grade on Sept. 7. A three-story, roughly 50,000-square-foot addition was built onto Fisher Hill to create an expanded 97,000-square-foot building that is expected to serve Orange’s educational needs for at least 50 years.

“It’s a lot of work to get to where we are today, and I can’t believe we’re so close to being done,” said Martin Goulet of Hill International Inc., the company managing the project on behalf of the town. “It’s exciting.”

Students in kindergarten through third grade went from Fisher Hill Elementary School’s pre-existing section to the new addition when winter break ended on Jan. 3 and remained there until the academic year concluded. Students in those grades will return to the pre-existing section, which has been gutted and renovated, and Dexter Park students will be taught in the new addition.

Goulet said asbestos was removed from Dexter Park prior to demolition, but the public is still not permitted in the area during the work. Goulet, who plans to retire in December after 47 years in the industry, also mentioned that two temporary buildings constructed in 1971 to serve as classrooms had already been knocked down by 12:15 p.m. on Monday. He joked that he’s not sure how temporary those structures were, considering they were built when he was a high school sophomore.

Goulet said his favorite part of any project is seeing students’ faces when they walk into a new school for the first time.

“It’s worth the five years of effort it took to get here,” he said.

The final product will feature 32 classrooms between the pre-existing section and the addition, as well as a new entrance and a learning deck outside the school’s media center and science, technology, engineering and mathematics (STEM) classrooms. The new entrance will have unbreakable School Guard Glass windows to protect students and staff members against those who would do them harm. The gymnasium will also be 30 feet bigger.

The Massachusetts School Building Authority, a quasi-independent government authority, designated Dexter Park Innovation School a Category 4 school in 2006 — its lowest rating. Voters approved funding in 2018 for a feasibility study concerning the Dexter Park issue and to come up with options to repair or replace it.

“It’s immensely gratifying. I mean, Dexter Park, although it has an emotional attachment for some people, its useful life was long ago extinguished,” said Bruce Scherer, chair of the Orange School Building Committee. “And the vision of the architect is that ... the new Fisher Hill campus will take full advantage of [the fact] there will be a pollinator meadow and you’ll be able to see it very clearly from Fisher Hill.”

The project costs $45 million, with Orange on the hook for roughly $22 million.

Scherer explained he hopes to hear back soon regarding state and federal grants to install solar arrays on the new school’s roof.

He also mentioned he agreed to be on the Orange School Building Committee six years ago because his daughters and grandchildren have all been students at Dexter Park.

“I felt it was my responsibility,” he said.

Reach Domenic Poli at: dpoli@recorder.com or 413-930-4120.