The question is as old as the construction of modern cities: How do you get unskilled, unemployed residents hired onto big building projects to share the wealth of a redevelopment boom?

The District has come up with an innovative answer that federal labor officials are hailing as a model for the rest of the nation.

The new Washington Convention Center under construction at Mount Vernon Square is the largest project ever undertaken by the city. A plan announced yesterday would enroll at least 100 residents in a one-year "pre-apprenticeship" called the Step-Up Initiative. They would be paid $7 to $8 an hour, plus health insurance, while being introduced to all the construction crafts at the huge site.

On-the-job training would be supplemented with classroom lessons. Then the residents would be eligible to join any of the construction trades' regular apprenticeship programs, leading to careers as skilled union journey workers.

It sounds simple, but it is historic. It involved an unusual improvisation on strict federal labor laws, and it required unions and construction companies to set aside their typically wary relationship to cooperate.

"This is truly a remarkable event," said Anthony Swoope, administrator for apprenticeship training at the U.S. Department of Labor, as the agreement was signed in the Carnegie Library at Mount Vernon Square.

The signatories included the city, the Washington Convention Center Authority, the local Building and Construction Trades Council and Clark/Smoot, the joint venture of Clark Construction and Smoot Construction that is building the center.

While the model may spawn imitators on big construction jobs around the country, in the District it is calculated to address long-standing complaints that residents have not benefited from major projects. For example, while the builders of MCI Center were required to hire 50 percent of the construction work force from the District, managers said residents lacked the skills for the highest-paying jobs.

Residents of Shaw, neighbors of MCI Center and of the convention center, couldn't make it out to places like Upper Marlboro where union apprenticeship training takes place, said D.C. Council member Jack Evans (D-Ward 2). Many residents also did not have even the basic skills needed to get into the apprenticeship programs.

The pre-apprenticeship program will be located in Shaw, in a building still to be chosen. Teachers will be union members and construction managers.

Similar arrangements have been used by the U.S. Department of Housing and Urban Development to put public housing residents to work building new housing, but the model has never been tried for commercial construction. Gregory Irish, director of the D.C. Department of Employment Services, said the city will consider applying the model to other big projects relying on city assistance.

Federal and city labor officials scrutinized the agreement to make sure it complied with the 1931 Davis-Bacon Act, which sets prevailing wages and work standards on this type of job. The Labor Department denied an outright waiver of Davis-Bacon, but it approved the new category of apprentice at wages slightly lower than union scale.

With the program open to only 100 or so workers, some Shaw residents are skeptical that the plan would have a big impact on the neighborhood where many families struggle to make ends meet. "This looks like a snow job," said Leroy Thorpe, an advisory neighborhood commissioner. "This is something to appease the community."