As Charles Lai recently strode out of the Museum of Chinese in America's new building, he couldn't stop smiling.

"Excitement is not the word," said Lai, executive director of the museum. "We've been waiting to get this thing going forever and a half."

Lai had stopped by the new MoCA building at 211-215 Centre St. to check out the progress on interior construction, which started in mid-March. He hopes to move the museum from its current location on Mulberry St. to its new home by early next year.

The new space has a lot going for it, Lai said. At 14,000 square feet, the Centre St. loft is six times bigger than the museum's space on Mulberry St. Just as exciting, he added, is that renowned architect Maya Lin designed the new museum space.

"It's been a labor of love," said Amanda Heng, spokesperson for the museum, as she walked through the cramped exhibit space on Mulberry St. "At the same time, we're in need of a change."

The new museum is all about change, down to the neighborhood in which it sits. That block of Centre St., between Howard and Grand Sts., was not part of Chinatown 50 years ago. The neighborhood was industrial and 211 Centre St. was a prime example: It housed a machine repair shop.

Over time, Chinatown expanded from its birthplace at Doyers and Pell Sts., and now MoCA's expansion is part of the larger story of Chinatown's growth, Heng said. Replacing an industrial use with a museum "is a very significant change," she added, "but we're trying to honor the space."

Lin's design for the museum features bronze, earthy tones with lots of glass and wood. Lin will retain or reuse as much of the repair shop's original wood as possible.

It will cost $15 million to build out the museum and start the programming, and MoCA has raised $10 million so far, Heng said. The Lower Manhattan Development Corporation gave MoCA $2 million in a community enhancement grant last fall.

The Mulberry St. museum several blocks away only had room for one major exhibit, entitled "Where Is Home?" The new museum will have six new exhibits, including "America: Staking Claims," focusing on American immigration laws, and "Made in America!?," which will explore how globalization influenced American culture. To personalize the exhibits, MoCA will display films of people narrating their stories.

When the new museum opens, the Mulberry St. space will become an archival research center, so the public can view MoCA's extensive collection of photographs and documents. The museum is raising money to possibly renovate or expand that space, which could take several more years.

MoCA's current location has been mostly closed to the public since February, but the museum still holds historical walking tours of the neighborhood. The museum also hosts several school groups a week in its small exhibit space, which doubles as a conference room. At its peak, the Mulberry St. location drew 120,000 visitors a year. Heng hopes to surpass 300,000 visitors a year in the new location.

In the past, MoCA has had trouble squeezing in all the visitors who want to see the exhibits, Lai said.

"It pains me on a personal basis -- that we have to end up turning away school children," he said. "How dare we turn them away?"

That's a problem Lai hopes he will never face -- or at least not for a while -- once the new museum opens. The new MoCA will have a special entrance just for school groups and far more room to accommodate them.

To Lai, the museum has a dual role: To serve as a tribute to the ancestors of Chinese Americans, and to teach that history to a new generation. The community has been waiting for years for the museum to open, and Lai is eager to deliver.

Workers have already gutted the first floor, an expansive 7,000-square-foot loft space. The highlight will be a sunlit courtyard in the center, which will diffuse natural light over the exhibits. As in a Chinese house, each section of the exhibit will open into the courtyard.

For now, naked bulbs hang from the ceiling, illuminating the building's original, peeling columns, which divide the space. The columns will be part of the finished product, as will dark wooden floorboards that are now protected by a layer of plastic and plywood.

The first floor will remain largely open. Most visitors will enter the museum on Centre St., where Lin designed a new facade of wood, concrete and bronze. As they enter, visitors will pass the Journey Wall, a mosaic of 300 bronze tiles. Lin designed the wall to honor the museum's donors in Chinese and English, but each tile will also include the donor's country of origin and current hometown, creating a display of personal journeys.

From the entrance, visitors will move into a reception area and tea room, which open into several large gallery spaces. The galleries will hold both core and rotating exhibits, allowing MoCA to display items that have been sitting in storage. Heng is excited about the new museum store, which will sell children's books and items designed by Chinese and Asian American artists. The current museum store is limited to a bookcase behind the reception desk.

School groups will use the museum's Lafayette St. entrance, which will funnel them into a cultural resource center that will also host youth activities. After school hours, Heng envisions the space as a hangout for local children, teenagers and families, with programs like film screenings and roundtable discussions.

The lower level of the new building will house a 100-seat auditorium, offices, a conference room and a studio. Artists could use the studio to create pieces for exhibit, but the creative process itself could also become an exhibit, Heng said. For example, visitors might be able to watch artists prepare fabric for an upcoming fashion display about a Chinese dress called the qi pao.

Several meeting and reception spaces in the new museum will be available for rental and community use. Chinatown groups will use the spaces for meetings and forums and residents will be able to attend educational programs like language classes

MoCA's offices are still in the old location at 70 Mulberry St., where they will remain until the end of the year. In a small gallery shaped like the inside of a Chinese lantern, a condensed version of MoCA's core "Where Is Home?" exhibit is on display. It includes a sparkling Chinese opera costume, cracked suitcases and brittle restaurant menus from the early 20th century.

Lai and co-founder Jack Tchen started pulling these objects out of dumpsters in the 1980s. Men who had emigrated from China decades earlier were dying without families, partly because the 1882 Chinese Exclusion Act had made it difficult for them to reunite with families left behind in China or to remarry in the United States. The act was repealed in 1943.

When the men without families died, their possessions ended up on the street. Lai and Tchen gathered armloads of artifacts and started the museum in a basement. They hurried to collect oral histories, letters and photographs from older residents before their story was lost, expanding the focus beyond New York.

As Heng stood in the center of the new museum, electric saws buzzed on the floor beneath her. The space's 14,000 square feet may not sound big, she said, "But it's phenomenal to us. It's a start."

If the museum does well, it could someday expand onto the upper floors of the building, which now house offices and commercial space. Gesturing toward the ceiling, Heng smiled. "Hopefully we'll move onward and upward," she said.