The Christian Science Church got the OK to raze its 1970s-era concrete chapel and can now proceed with development plans, apparently ending one of the city's fiercest battles over historic preservation.

Proposed plans call for building a smaller church as part of a mixed-use project at 16th and Eye streets NW just north of the White House.

Harriet Tregoning, D.C. planning director acting in a capacity as the mayor's agent for historic preservation, ordered the city on Wednesday to issue a raze permit. She called the design of the church and adjacent office building "experimental" and "adaptive reuse of the church building is not a viable option."

While the decision is a victory for the church -- which says the 38-year-old building demands expensive upkeep and maintenance for the small congregation -- it is a blow to historic preservation groups, which consider the church a prized example of Brutalist architecture, a form of midcentury modern design that includes the FBI's J. Edgar Hoover Building. The church was designed by Araldo Cossutta, a partner of famed architect I.M. Pei, and completed in 1972.

The two sides have been debating the building's merits since the early 1990s, when a consortium of preservation groups filed a landmark application to protect the building from being demolished at that time. The debate was rekindled - and the building was ultimately landmarked - in 2007, after the Third Church's mother church in Boston sold the underlying land to ICG in April 2007.

After the city denied a raze permit based on the landmark status, the church sued in August, potentially setting up a legal challenge that may redefine local governments' ability to regulate land use by religious institutions. At a hearing in April, a federal judge lashed out at the Historic Preservation Review Board for its attempts to prevent the church's demolition.

Tregoning said the church should not be razed until the church received city approval for a plan for a new facility.

The Christian Science Church issued a statement Wednesday saying it is moving quickly with Kerns Group Architects of Arlington to create conceptual plans based on discussions with its Advisory Neghborhood Commission and the Historic Preservation Review Board.

"During the long, arduous and costly process of obtaining permission to rebuild, we have continually reported that whatever we do will be consistent with the L'Enfant Plan, the Sixteenth Street Historical District, and the National Capital Framework Plan approved last year by the National Capital Planning Commission and the Commission of Fine Arts," the statement said. "That remains our full intent."

The statement said that the church's partnership with ICG Properties ended a year ago, but now it hopes to again join forces with ICG. Officials at District-based ICG could not be reached for comment.