A year after a fire forced UGI Corp. to evacuate all 350 employees from its King of Prussia corporate headquarters, the energy company on Tuesday cut the ribbon on its newly renovated offices.

A Dec. 16, 2009, electrical fire spread soot throughout the five-story, 100,000-square-foot building on North Gulph Road, forcing the company to relocate its employees to leased space in Audubon, said Marcia Vogt, UGI's facilities manager.

"It's quite an endeavor to move 350 people, including all the incidentals," Vogt said.

UGI used the opportunity to renovate the 38-year-old building, replacing heating, air-conditioning, lighting, and computer systems.

"The fire turned out to be a blessing in disguise," Vogt said. "The building was quite dated."

The smoke damage was so extensive that virtually every piece of paper in the offices needed to be deodorized in special ozone chambers constructed during the renovation.

"We got rid of all the furniture - the smoke smell was so embedded in everything," she said.

The work was coordinated by Belfor USA, a disaster-recovery company with local offices in Exton.

Vogt said UGI was still negotiating with its insurance carrier to determine how much of the renovation costs will be covered.

According to UGI's annual report, it has budgeted about $12.7 million for headquarters renovations.

Contact staff writer Andrew Maykuth at 215-854-2947 or amaykuth@phillynews.com.