Arlington’s Pentagon renovation project was the most significant construction projects of 2011, the Associated General Contractors of America announced recently. As a result, the project’s contractor, Hensel Phelps Construction Co., was the grand award winner while 15 other firms received the association’s Alliant Build America Award in other categories.

“These projects demonstrate the qualities that have made the construction industry great: hard work, ingenuity and world-class skill,” said Kristine Young, the association’s president and the CEO of Des Moines, Iowa-based Miller the Driller. “Contractors like these are not only building exceptional projects, they’re building a better, more prosperous America.”

Hensel Phelps was tasked with renovating four sections of the Pentagon just three days after the 9/11 attack. The team was confronted with an accelerated schedule, new stringent security upgrades, the need to harden the exterior envelope, and the added responsibility of supporting recovery efforts from the attack. The team completed the renovation nearly four years ahead of the original schedule, allowing 25,000 Pentagon employees to continue working with minimal disruption.

The Alliant Build America Awards recognize the nation’s most significant construction projects. A panel of judges, representing all areas of construction, evaluated a record number of submissions this year, assessing each project’s complexity, use of innovative construction techniques and coordination with partners, among other criteria. The awards, which were announced during the association’s annual convention in Honolulu, are considered by many to be the most prestigious recognition of construction accomplishments in the U.S.