In response to calls for preservation of the historic First Security building, the LDS Church said Wednesday the building can't be saved because problems with its old design make it too difficult to modernize.

Dale Bills, spokesman for The Church of Jesus Christ of Latter-day Saints, said in a statement that the building is not fit for office or residential use and emphasized that in the project's plan.

"Architects, engineers and planners on our redevelopment team have spent 24 months carefully evaluating all options for this building," said Bills' statement. "Even after a seismic retrofit costing tens of millions of dollars, the building still could not adequately accommodate office or residential tenants in a competitive downtown marketplace. The high costs of restoration could not be recouped."

A Utah historic-preservation advocate said Wednesday that if the church can't save the building for office space, maybe it should be used for something else, rather than being torn down.

Kirk Huffaker of the Utah Heritage Foundation acknowledged the obstacles the church says stand in the way of preserving the building, which has stood at the corner of 100 South and Main in Salt Lake City since 1919. The building, also known as the Deseret Building, is slated for demolition as part of the church's City Creek Center downtown renovation project.

"Our ideas are about alternatives to office space in the building," Huffaker said. The building "is not necessarily ideal" for office space and might be put to residential use, he added.

He suggested a new office tower could be built next to the First Security building, providing office space and also serving as a possible bolster to stabilize its seismically unsound older neighbor.

Bills would not comment further on the building or on Huffaker's statements, but his statement was added Wednesday to the Downtown Rising Web site, www.downtownrising.com, in a frequently asked questions section on the City Creek Center.

The Web site lists specific reasons the building cannot be preserved:

• Its floors are too tightly spaced together, leaving inadequate room for ducting and other equipment.

• Structural support columns are too close together to accommodate modern office layouts.

• The facade is largely made of "fragile terra cotta that cannot be removed and replaced without significant damage to it."

Church officials have previously said the possibility remained that the building's facade — which is adorned with lions' heads, elaborate Indian and buffalo head medallions and classical columns — could be preserved.