PEABODY – Purchased for Christmas but never decorated, the pine tree that spent the winter in Beverley Griffin Dunne?s backyard had its moment in the sun Thursday as construction workers hoisted it high up onto the new Higgins Middle School?s steel skeleton.?It?s funny the way it worked out,” Griffin Dunne said as she explained how her family decided to mark the holidays in a low-key fashion while her husband, Robert, served with the Navy in Afghanistan.Mayor Ted Bettencourt praised Griffin Dunne Thursday as a key player in the Higgins project, and said the tree mounted onto a steel beam symbolizes, for construction workers and city officials alike, the end of a long, tough chapter in the school?s construction.Workers labored through the winter erecting steel and doing other work, spending some days clearing a blizzard?s worth of snow before they got to work.?They worked outdoors with no complaints and barely a slowdown,” Bettencourt said.Lynn resident Eric Olson supervises the project?s plumbing, heating and ventilation installation work and said February?s storms challenged workers.?The northeast wind coming through was tough,” he said. “You can?t do much to stay warm.”Launched in 2012, with the state committed to reimbursing the city for just over half of the project?s $92 million cost, Higgins is scheduled to open in September 2016. Practically abutting the existing Higgins School, the new building will have a three-story academic wing and main building with a gymnasium, auditorium and other features.?The largest middle school in Massachusetts will be here in Peabody,” Bettencourt said.Higgins Principal Todd Bucey can?t wait to take the helm in a brand-new building. He started teaching social studies in the existing Higgins 20 years ago and has been the school?s principal for six years.Bucey said 1,300 sixth- through eighth-graders attending the new Higgins will benefit from its upgraded teaching technology.?Right now, we are doing a lot with the limited technology we have,” he said.Bettencourt said the new Higgins is the first public school built by the city since the Carroll and Brown elementary schools were constructed in 2000 and 2001. Once the project is completed, the existing school will be demolished to provide space for athletic fields.Griffin Dunne said she was happy to see the workers who braved the winter building the school hoist her neglected tree onto the school. Her husband, Robert, has returned to the United States and will finish up his Navy duties before celebrating a delayed Christmas with his wife and their four children.