The Capitol Visitor Center in Washington, D.C., opened its doors on Dec. 2, 2008, but it's been in the works for years—decades, even. The D.C. office of architectural firm RTKL Associates has design studies for the center dating back to the 1980s, although the project didn't really take off until 1999, says senior vice president Rod Henderer. The construction of the 580,000-square-foot underground facility, started in 2002, became somewhat of a joke over the years as deadlines repeatedly got pushed back and costs escalated at every turn. Initially, the center was to cost $265 million, with $100 million of that privately raised. In the end, taxpayers footed the majority of the $621 million bill.

Did we get what we paid for? On the outside, yes. The center lies beneath a new plaza on the east side of the Capitol, facing the Supreme Court and Library of Congress. RTKL designed the plaza to fit in quietly with Frederick Law Olmsted's historic Capitol landscape, and the lighting is appropriately subtle, illuminating the grounds at night while making the Capitol and its dome the primary focus. Restored Olmsted post lanterns with metal halide sources ring the plaza, each emitting about 2 foot-candles onto the East Front. Floodlights atop the visitor center's two elevator towers illuminate the iconic dome. “The dome is lit from 360 degrees for the first time ever,” says Scott Matthews, partner at New York–based Brandston Partnership, which executed the center's lighting design.

Two 70-foot-by-30-foot skylights—surviving elements of RTKL's original design proposal—might be the most striking design element of the center's interior. Located in the Great Hall, they afford visitors grand views of the Capitol dome. Following Sept. 11, 2001, numerous security features were added to the center's design, and “one of the concerns I had as a result of 9/11 was that we would lose the skylights,” Henderer notes. “But after extensive review by different agencies, everyone recognized the importance for views of the dome and natural light.” Four 20-foot-by-20-foot skylights, all on a line adjacent to the Capitol, are located above the orientation theaters and stairways of the House and Senate spaces.

Budget overruns aside, one regrettable result of the project's missed deadlines is a lighting design that's not as cutting edge as it should be. In the past few years, lighting technology has advanced significantly and energy efficiency has emerged as a prominent issue.

While nothing officially has been proposed, there already are rumblings about updates to the lighting design just months after the center's opening. “We are contemplating a retrofit program to see whether it is feasible to go back in and work with the manufacturers to retrofit [the lamps] out,” Matthews explains. “Think about the installed base of incandescent and halogen lighting—it's immense. It'd be good to come up with a retrofit program for those.” It would be a lengthy research and development process before any plans even could be proposed to the Architect of the Capitol, but starting the discussions now might be wise as the phaseout of incandescent bulbs by 2014 takes effect and energy efficiency is a continuing concern.