The US Capitol Visitor Center

Quick Facts


Washington, DC


Government Building



Delivery Method

Plan & Spec

Square Footage


Project Summary

The award-winning United States Capitol Visitors Center is an underground extension of the United States Capitol building and, at 580,000 square feet, it is the largest addition to the Capitol ever built. The CVC occupies an area approximately three-fourths the size of the Capitol itself and is a multi-use structure operated by the Architect of the Capitol. The architectural finishes are rich with granite, limestone and bronze. Twin skylights, two indoor fountains and a number of statues of historically significant leaders highlight Emancipation Hall, the gathering hall and centerpiece of the Center.

In addition to serving as the starting point for public tours of the Capitol building, CVC includes an extensive exhibit gallery containing various state-of-the-art virtual tour modules and a host of national treasures. The building also houses a new substation of the U.S. Capitol Police, three theaters, two television recording studios, a large cafeteria and catering kitchen, swing spaces for the House of Representatives and Senate, Congressional hospitality suites and several auditoriums.

KDB’s work included the installation of the plumbing, heating, ventilation, air conditioning, sheet metal and controls. The HVAC system has a primary steam heating system, including clean steam generators for humidification and eight large heat exchangers for hydronic reheat loops and domestic hot water. The steam and chilled water is provided from the Capitol Power Plant. Kirlin installed approximately 800 feet of high pressure steam/condensate piping in an underground utility tunnel. The HVAC also includes a chilled water system that feeds the 25 air handling units and numerous fan coil and computer room air conditioning units for cooling data hubs and recording studio equipment.

A large filtered exhaust system includes six 60,000 CFM exhaust fans. KDB’s work also included piping to 42 different pieces of kitchen equipment, as well as 36 bathrooms and six display fountains that adorn the CVC’s landscape. The CVC is controlled by a fully integrated native BACNet DDC controls system.