The vertical expansion to the Colorado Convention Center added 200,000 sq ft to the 2.2 million sq-ft center built in the early 1990s. The project included a ballroom, pre-function space and a rooftop terrace, as well as providing an update to the lobby areas. The team faced two major challenges—completing the work on the convention center while it was operational, and maintaining the look of the well-known “blade roof” while building the addition to the structure.

“The Colorado Convention Center Expansion is an architectural and structural marvel that … faced many obstacles, including procuring 18 million pounds of steel and over $3 million worth of kitchen equipment, and coordinating the placement of a million-pound crane on the existing roof of an operational facility,” says Jonathan Popiel, project manager at Hensel Phelps, the project’s general contractor. “Despite these challenges, the team achieved over 1.5 million work hours without a single lost-time safety incident. This success is a testament to the design-build approach, teamwork and dedication of everyone involved.”

To ensure worker safety during the large amount of elevated work, Hensel Phelps instituted a “ladders last” policy, which requires workers to first use a scissor lift or a scaffold for overhead construction, with ladders as a last option. Horizontal lifeline systems for steel erections were also put into place on columns, girders and beams as an additional safety feature.

The expansion project was completed on time and on budget in February 2024.