The grand old Carnegie Library at Mount Vernon Square is but a month away from being returned to its former glory as the newest museum in the city’s extensive collection.

But the City Museum is setting itself apart from the other bigger, more established museums. This intimate 60,000-square-foot building (compare that to the National Air and Space Museum’s whopping 161,145 square feet of exhibition floor space) housed in the historic Carnegie Library is set to occupy its own niche in the District’s museum market: It will be the only museum to focus solely on the culture and history of the city’s residents and not the federal history.

Still wrapping up the last bits of its $30 million facelift, the museum remains in a mess of construction, with paint and sawdust wafting through the air during a recent tour. But the Historical Society of Washington, D.C., which will run the museum, isn’t worried. Officials are confident that by May 15, when the opening ceremony and ribbon cutting roll around, the museum will be ready to impress and all the warts of reconstruction and restoration will be worth it.

Meshing the historic exterior with the need for a modern interior has required painstaking planning and design.

“Space and wiring have been our largest problems so far,” said Pamela Woolford, spokeswoman for the Historical Society of D.C. “It’s a 21st-century project, and these kind of things need to be taken into account.”

Preserving the building is part of the museum’s mission, since the society considers the Carnegie Library one of the District’s great assets. However, blending the museum in with its large looming neighbor, the new Washington Convention Center, was also taken into account, and architectural elements were used to create a more seamless transition between the two distinct styles.

From bones to books, the museum is looking to encompass all the city has to offer. With a sizable portion of the first floor dedicated to an archeological exhibit and lab space, the museum is looking to become the official repository for the Archaeological Society of D.C.

The building won’t stray too far from its literary roots. The Historical Society will make its extensive collection of books, maps and other resources available in the old children’s reading room on the third floor. There students, history buffs and scholars can all gather for research.

For those looking for a little more entertainment, the City Museum has that covered as well. The street entrance level will house a theater with a multimedia show, two smaller community and collection galleries, a storefront gift shop and a cafe in addition to the overview exhibit.

The multimedia show will run a special piece created for the museum titled “Real People Live Here.” It incorporates puppets as well as video footage of D.C.-based actors portraying historical figures and actual Washingtonians talking about their experiences.

“We are really excited about the show. It has been described as a cross between Monty Python and Cirque du Soleil,” Woolford said.

The community galleries will rotate different neighborhoods and cultures through the space every six months. They will showcase portions of the city visitors and even locals may not have previously visited. The first two communities on display are Mount Vernon Square and Chinatown.

“We want to encourage people to go off the beaten path and explore the lesser-known and out-of-the-way parts of the city,” Woolford said.

The museum is planning other community-building events, such as a lunchtime music series on the front steps and a citywide scavenger hunt scheduled for May 17.

Admission for the museum will be $3 for adults and $2 for students and seniors. The multimedia show will cost $5 for students and seniors and $6 for adults. Admission to both is free for members of the museum. Access to the library and main hall will be free to all visitors. For more information on the City Museum, visit the Historical Society Web site at www.hswdc.org.