A group of 20 Riverside residents are suing the University in an effort to block the construction of a new graduate student dormitory across the Charles River in Allston.

The group filed the lawsuit against the University in Middlesex Superior Court last week, claiming that the proposed 15-story building violates a recent decision by the Massachusetts Historical Commission (MHC), a state board that said Harvard’s building would have an “adverse affect” on the Charles River Basin Historic District.

In addition to the University, the residents are also suing the Massachusetts Historical Commission (MHC) for not acting on its decision.

Residents involved in the suit said the proposed building does not fit in with the size of existing buildings, and will harm views of the Charles River by creating large shadows across the area.

“You just don’t build a skyscraper on the river,” said Cob Carlson, one of the residents suing the University. “We’re concerned about our view, being able to see the sun go down, and not having shadows cast on the river.”

But Harvard officials say they have met all requirements to begin construction on the building: they have received approval from the Boston Redevelopment Authority and the Boston City Council, as well as the Allston-Brighton Task Force, a group of residents and business owners in the area.

“We’ve gone through an extensive public review process,” said Mary H. Power, Harvard’s senior director of community relations. “We believe we have already fully complied with the recommendations.”

Harvard’s original proposal for a 22-story building on the site drew strong criticism from residents and city officials last spring, leading the University to modify its plans down to the current 15-foot proposal.

In addition to the size change, the University increased the setback for the project, creating 18,700 square feet of new green space along the Charles River.

Brian S. McNiff, a spokesperson for the MHC, said the board is currently reviewing additional design information provided by the University on the project. McNiff added that the board has no power to block the project, and is instead working with Harvard and its architects on modifications to minimize the impact of the building on the area.

“The material they have submitted is still under study,” McNiff said. “The board will attempt to negotiate on what the builders want to do and what we think is appropriate. This is not a procedure that would halt the building’s construction.”

Initial construction has already begun on the dormitory, with an expected completion date of July 2003. Harvard Planning and Real Estate is marketing the building in a housing brochure mailed with Business School acceptance letters.

Power says that she is disappointed that the residents have decided to take legal action, saying the purpose of the proposed 240-unit building is to help alleviate the housing crunch in Boston and Cambridge caused by graduate students living in residential areas.

Harvard currently provides on-campus housing for nearly all undergraduates and about 40 percent of graduate students.

“The mayor of Boston issued a challenge last year to the University to house at least 75 percent of its graduate students to relieve pressure on the local housing market,” Power said.

“This project helps to achieve that goal.”

While residents said they are not opposed to the University housing more of its graduate students, they decided that legal means were the only way to halt construction of a building they feel is just too large and will have a negative impact on the area.

“Harvard just ran this through for approval,” Carlson said. “We don’t have any alternatives.”

—Staff writer Imtiyaz H. Delawala can be reached at delawala@fas.harvard.edu.