Stewards of the iconic buildings and grounds of Capitol Hill since 1793.

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The Old Supreme Court Chamber is the first room constructed for the use of the nation's highest judiciary body and was used by the Court from 1810 until 1860. Built by Benjamin Henry Latrobe, it was a significant architectural achievement, for the size and structure of its vaulted, semicircular ceiling were virtually unprecedented in the United States.
The Old Supreme Court Chamber is the first room constructed for the use of the...

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A crowd of people visiting the Capitol during visitor hours
Please note: Many of these Capitol Hill buildings are working office buildings...

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Photo with enclosed area on Dome.
Update: November 2014 Scaffoldin​g and Restoring PhaseThe scaffolding assembly...

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Statue of John L. “Jack” Swigert, Jr.
Visitors to the Capitol are often drawn to the "big ticket" items,...

Capitol Power Plant

Employees at the Capitol Power Plant working on a project

The AOC Capitol Power Plant jurisdiction (CPP) is responsible for managing and operating the Capitol Power Plant. The Power Plant operates 24 hours per day, 365 days per year to provide steam and chilled water service to heat and cool the Capitol, the Capitol Visitor Center and 22 other facilities located on or near Capitol Hill.

Commissioned in 1910, the Power Plant originally provided the Capitol with both steam and electricity. Today, the Power Plant provides steam and chilled water utility services to both congressional and non-congressional facilities, the latter of which is provided on a reimbursable basis.

The jurisdiction procures electricity from commercial suppliers. In addition to the central steam and refrigeration plants, the jurisdiction maintains an administration building and the tunnel distribution and metering systems required to deliver these utilities. The jurisdiction is responsible for the daily care, maintenance and operation of the Power Plant facilities. In addition, the CPP continues to implement operational changes and pursues modernization efforts to ensure the most cost effective and energy-efficient operations.