Capitol Exterior Preservation - Stone and Metal

A multi-phased project designed to address deferred maintenance, extend the life expectancy of the deteriorated stone and to replace missing elements of the U.S. Capitol Building.

Work for Phase 4 will include cleaning of the stone and pediment sculpture, replacement of the mortar and sealants at all of the stone joints, treatment of the carved stone and pediment sculpture, replacement of stone where elements are missing or cannot be repaired, and replacement of the bird deterrent systems on the East Front of the U.S. Capitol.

Phase 4 is anticipated to begin late 2025.

Stone Preservation on Capitol Hill

Frequently Asked Questions

Why is/will part of the Capitol Building covered in scaffolding?
The Architect of the Capitol (AOC) is preserving the building's exterior stone and metals. The project will prevent water infiltration, slow deterioration of the stone and corrosion of the metals, repair damage and remove soil and stains.

Phase map for the U.S. Capitol exterior preservation project and stone work.

Phase 1 - North Extensions, Senate Wing: Completed 2017
Phase 2 - South Extensions, House Wing: Completed 2020
Phase 3 - West Front: Completed 2024
Phase 4 - East Front: Anticipated to begin late 2025

What is the purpose of the project?
The project is designed to prolong the life expectancy and preserve the historic features of the building. The project cleans, repairs and preserves the historic stone and the architectural metal throughout the U.S. Capitol Building's exterior.

Before and after stone restoration.

Why is the project happening now?
Previous surveying identified this project as critical and delaying this preservation would cause the building to deteriorate further and more of the U.S. Capitol Building’s historic fabric would be lost.

What are the benefits of the project?
This project will preserve the stone and architectural metals of the building and allow it to continue to function as the home of the United States Congress, the symbol of our democracy and for the enjoyment and education of future generations of Americans.

Stone & Metal Project Photos on Flickr

What will the Capitol look like during constructions?
The project will require scaffolding to execute the work. At night the scaffold and building will be lighted to assist workers as they perform their tasks. A scrim will cover the scaffolding to control dust and water spray.

What are the impacts of this project on visitors and staff?
To minimize the disruption to Congressional business, much of the project work will be performed at night, Monday through Saturday. Quiet tasks will be conducted during daytime hours. The windows will be screened to maintain privacy and safety during the project. Most doors will remain open for both entry and exit, while others will be for exiting only.

How can we ensure the project delivers good value to the taxpayer?
The AOC is committed to maximizing taxpayer value. Following full and open competitive bidding, a highly qualified contractor was selected to perform the first phase of the project. The contractor for Phase 2 and Phase 3 was selected from the AOC's Multiple Award Construction Contract, which was determined through an open competition bid process. The AOC will maintain close oversight to ensure the project quality is the highest possible, the project remains on time, within budget and minimizes disruption to the work of Congress.