Principal Clare Sullivan - a 30-year Avery School stalwart - planned to hold a closing ceremony Friday for the current and about to be "old" Avery Elementary School. She'll take down the Avery Pride banners that line the gymnasium and watch as schoolchildren play on a grass-less playground for the final time.

In less than 18 months, Avery students went from digging the first dirt to welcoming parents and state officials to their new $21 million school Thursday morning.

"I can remember a few short months ago when we gathered at what is now the 50-yard line of the new athletic field to celebrate the setting of a ceremonial beam on this new magnificent structure. At that time the discussion focused on a vision we had for the new Avery School," Town Administrator William Keegan said. "Today that vision is a reality."

Several state and local leaders praised the work of architects Dore and Whittier and Consigli Construction, as well as the School Building Rehabilitation Committee, which oversaw the construction.

But officials recognized they wouldn't be standing in a new state-of-the-art facility without a pretty large contingent - the voters.

Dedham voters approved a debt override for the project in January 2010 by more than 60 percent. The state's School Building Authority agreed to pay about $11 million from its fund.

"We don't tell you what to do, you don't tell us what to do," said Steven Grossman, state treasurer. "We work in a collegial and collaborative way. That's how great projects like Avery happen."

Former state treasurer Tim Cahill was in charge when the project was initially approved by the MSBA.

The new school is a quite significant upgrade than the 1921 building just a few blocks away.

For one, the new building has a "cafetorium" and a full-service kitchen that allows students to eat together, and not in classrooms. The current building has one set of student bathrooms - in the basement - the new one has many more and on every floor.

The classrooms are larger and all equipped with Smart Boards, and feature individual teaching space.

With students moving in after April vacation, the 30-acre school campus will have three operational schools, 1,700 students and $61 million worth of investment in the past 10 years, according to selectman Michael Butler.

"The beneficial impact on education, the neighborhood and the entire town cannot be understated," Butler said.