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.