It took longer than expected, but what was once a bowling alley on the old Navy base in North Charleston is now the U.S. Department of State’s new human resources service center.

Part of the department’s cost-saving strategy, the 45,000-square-foot red-brick building contains a call center, offices with rows of yet-to-be-filled cubicles and videoconference and training rooms.

After moving from the nearby passport processing center in late August, workers there answer most current or former diplomats’ travel or benefit questions and interview aspiring State employees via videoconference, among other tasks. The 50-member workforce is expected to swell to more than 200 by the end of 2014.

The renovation of that building on the old Navy base cost more than $10 million.

Speaking to a small crowd sitting on wooden chairs on Dyess Avenue, the commander of the Charleston District of U.S. Army Corps of Engineers, Lt. Col. Edward P. Chamberlayne, thanked everyone for their “unlimited patience” as his team overcame the “tremendous challenge” of turning the former old rec center into “world-class” offices.

Utility piping problems, asbestos in tiles and changes to the roof design were but a few of the thorny issues the construction workers confronted during the renovation.

“We wanted to deliver a quality product in the end, and that’s what you have in front of you today,” he said.

Ambassador Linda Thomas-Greenfield, who became director general of the Foreign Service and director of human resources earlier this year after four years as top diplomat in Liberia, made the trip down from Washington, D.C., for the occasion.

It’s the latest piece of State’s plan to decentralize the capital while centralizing previously disparate functions, like human resources, she said, noting both land and labor are cheaper in the Charleston area than they are in Washington.

Just as the Navy was closing in the mid-1990s, State was looking for somewhere to place its finance office, Thomas-Greenfield said. The department eventually acquired four buildings.

The financial services operation opened in May 1995 with 10 employees; now it’s up to 800 people in three buildings.

Similarly, the passport office opened in May 2000 with 33 employees. Since then, it’s processed 24 million passports, grown to 800 employees and become the second-largest facility of its kind in the country.

North Charleston mayor Keith Summey welcomed the continued development at the bottom of the former Navy base. He credited former U.S. Sen. Fritz Hollings for repopulating the tract while in office with agencies like State and the Federal Law Enforcement Training Center.

“We like having the federal government’s presence in our community,” Summey said.

After it was a 24-lane bowling alley for the Navy, Building E was a gym for the Federal Law Enforcement Training Center, said Charles Enos, a contract architect on the project. Half of it was prefabricated metal and half was concrete masonry.

The decision to renovate rather than build a new structure was based on the building’s existing superstructure, including 40-foot pilings, and cost and space reasons.

“It would’ve cost an arm and a leg to build a new structure here,” Enos said, estimating the coast at $12 million to $15 million.

Design work began in 2007, and construction started in 2010 and finished earlier this year.

Amy Merritt, a 47-year-old Mount Pleasant resident who started at the human resources office in 2008, was happy to move into the new call center, which supports some 270 State Department offices around the world. It contains some of the “green” features that make the building eligible for a LEED gold rating from the U.S. Green Building Council, like special light-concentrating sky lights called solar tubes.

“We love everything being new,” she said.

Her colleague, Ryan Jennings, reveled in the simple pleasures of his new office.

“The chairs are the best,” he said. “It’s like sitting on a big rubber band.”

Reach Brendan Kearney at 937-5906 and follow him on Twitter at @kearney_brendan.