O'Neill House Office Building

The O'Neill House Office Building is a modern government structure along C Street Southwest with seven floors that combine limestone and glass in its design. Inside, it houses offices for House representatives and sections of the Department of Health and Human Services.

The structure was built in 1963 as Federal Office Building No. 8 and initially housed laboratories for the Food and Drug Administration. A major renovation in 2008 transformed its interior and led to its later naming in honor of the former House Speaker.

The building honors a former Speaker from Massachusetts through its name, reflecting his long service in Congress. Visitors can observe how the modern design supports the daily work of House representatives today.

The building is located in the Southwest Federal Center with accessible areas and modern office spaces that feature updated climate control and energy-efficient systems. Visitors should know that this is an active government building, so some sections may have restricted access.

The 2008 renovation introduced two large atriums with skylights and glass curtain walls that replaced the original limestone exterior on several sides. These new open spaces filled with natural light changed how staff and visitors experience the interior.

Location: Washington, D.C.

Inception: 1963

Architectural style: modern architecture

Floors above the ground: 7

Address: 200 C St SW, Washington, DC 20024

GPS coordinates: 38.88539,-77.01442

Latest update: December 7, 2025 20:41