Hart Senate Office Building

As early as 1891, when the now-demolished Maltby Building just north of the Capitol was acquired, the Senate provided office space outside of the Capitol for its Members, committees, staff and other support operations. The Russell Senate Office Building, completed in 1909, was the first structure designed especially for the Senate, followed by the Dirksen Senate Office Building in 1958. As in the case of these earlier office buildings, the Hart Building was a material response to the growth of the nation and the corresponding growth of the duties of the senators.

As early as 1967, the Senate began to experience a strain on its existing facilities and initiated the process which led to the creation of the Hart Building. In this early period, it was widely held that a simple addition to the 1958 Dirksen Building would be adequate. Under this assumption, Congress in 1972 authorized new construction for the Senate and made an initial appropriation for the project.

Under the direction of the Senate Office Building Commission, Architect of the Capitol George M. White invited a number of nationally prominent architects to interview for the project, which led to the commissioning of the firm of John Carl Warnecke & Associates as associate architect on May 1, 1973. With the Architect of the Capitol, Warnecke explored alternatives to the replication of the plan, style and finish of the Dirksen Building. It became clear that an entirely original structure would be necessary to cope with the space and design requirements of the new building, now expected to include suites for 50 senators. The resulting building adjoins the Dirksen Building in Square 725, bounded by Constitution Avenue, Second Street, First Street and C Street NE.

With the way clear for a fresh approach, the architects set about designing a flexible, workable, durable building that would reflect the best of contemporary design and technology. The result was a nine-story structure with three basement levels and 1,271,020 square feet. The design has a simplicity and human scale that scrupulously avoids the costly classical ornamentation of the first congressional office buildings and helps disguise the building's bulk. However, the exterior, with its evenly-spaced vertical lines of windows, nonetheless recalls the regular rhythms and deep shadows of columnar buildings. The Hart Building was intended to be a graceful background building that, despite its size, would call little attention to itself. Its blend of contemporary minimalism and classical proportions allows the building to fit into its surroundings without literally resorting to anachronistic design motifs. Inside, the architects balanced the desire for modesty with the need to use permanent and therefore costly materials—mainly marble and bronze.

On August 8, 1974, the design of the "Dirksen Extension" was approved by the Senate Office Building Commission and the Senate Committee on Public Works. Approval was given after the concept and design had been opened to public scrutiny, during which time architects, critics, and neighboring residents were invited to evaluate and comment on the proposed structure. This was the first instance of public participation in the history of Capitol Hill building projects.

The unprecedented design included several additional "firsts" in the history of Capitol Hill office buildings. For instance, in response to the concerns for energy conservation which marked the 1970s, the design of the Hart Building illustrates how successfully conservation could be incorporated into architecture. The central, light-filled atrium and connected galleria provide a gathering space; the corridors and offices organized around them benefit from abundant natural light and views while a full 75% of exterior exposure is eliminated. Sunscreens help control summer heat gain while adding visual interest to the outside elevations.

One of the most significant innovations of the Hart Building is the concept of the "duplex suite." Each senator is provided with a dignified office with traditional sixteen-foot ceilings as found in the Russell Building. Adjoining this core space are two levels for staff that can be arranged in any manner thanks to demountable partitions that are easily moved. This allows each senator to customize staff space to suit individual needs. In the older office buildings such flexibility was impossible due to the static arrangement of rooms strung along a central public corridor, much like rooms in a hotel.

Conservation of historic resources had, by the 1970s, become a vital concern along with energy conservation. The Architect of the Capitol made the preservation of the neighboring Sewall-Belmont House a requirement for the design and site plan for the Hart Building. Simply clearing the site for new construction was no longer viable with a nearby significant Federal-style building. The Hart Building neatly avoided disruption of the house and its garden, which became the Belmont-Paul Women's Equality National Monument, part of the National Park Service, in 2016.

The first construction contract was awarded on May 20, 1975, and excavation began in December of that year. Work proceeded in a total of six phases, and the first occupant, Majority Leader Howard Baker, moved into his office suite in November 1982. Construction of the Hart Building took place during a period of rapid and unprecedented inflation; the national index of construction costs jumped 76%. As a result, some of the originally programmed work, including a rooftop restaurant and a gymnasium, was cut or deferred as a cost-saving measure. Later, the in-house construction management group and maintenance personnel from the Senate Superintendent's Office completed virtually all the deferred construction work, such as the Central Hearing Facility (SH-216). Construction costs for the Hart Building were thus held to a reasonable figure when compared with similar private sector corporate headquarters.

The completed building contained office suites for 50 senators, facilities for three committees and additional subcommittees, a subway extension connecting to the Dirksen Building and the Capitol, space for support services, and underground parking for 335 cars. Marble covered the walls and floors in public spaces like the atrium. Marble and limestone sheathe the exterior of the building. Both the interior and exterior of the building use bronze trim.

The large Central Hearing Facility, completed in 1987, was built to accommodate hearings that attracted significant public interest and media coverage. It is surrounded on three sides by spaces for television cameras and reporters, and the hearing room itself contains more space for seating, better acoustics, and lighting appropriate for television cameras. Three walls are clad in wood, while the wall behind the dais is white and gray marble with the Senate seal affixed in the center. The Central Hearing Facility has been the site of hearings for Supreme Court nominees, including Ruth Bader Ginsburg, Samuel Alito, Sonia Sotomayor and Neil Gorsuch. The 9/11 Commission also held hearings in this room.

Initially, the increased costs and contemporary design elements made the building unpopular with senior senators, so junior senators made up many of the first office suite occupants. Despite mixed architectural reviews, the design of the Hart Building made strides in planning, circulation, and adaptability, thus reinventing and redefining the congressional office building. While it has dignified classical proportions, it is a decidedly contemporary building. It uses durable materials to provide energy-efficient, flexible spaces and a modern working environment for its occupants.

In 2015, the Architect of the Capitol completed a roof and skylight replacement project. It included upgrades to the fall protection system and the installation of one of the largest federal solar panel systems in the Washington, D.C. area.

In March 1986 a monumental sculpture was installed in the atrium of the Hart Building. Mountains and Clouds was the last work of Alexander Calder (1898-1976), inventor of the "mobile," or suspended moving sculpture, and one of the most influential American sculptors of the twentieth century. This piece, designed specifically for the Hart atrium, is the only one in which Calder combined separate mobile and stabile (standing sculpture) forms in one work. On the day before his death, Calder was in Washington adjusting his model of the sculpture. Public funds for the work were sacrificed to help trim costs, but former New Jersey Senator Nicholas F. Brady revived the project by raising private funds to underwrite the installation. The Senate dedicated the sculpture on May 5, 1987.

The four clouds, the largest of which weighed a ton, were made of aluminum and installed first. They hung from a single shaft suspended from the roof and revolved above the 39-ton steel mountains, which rose 51 feet above the floor. To simulate the motion of real clouds, a computer-controlled motor generated random patterns for the clouds' movement, but the apparatus failed to achieve the sculptor's intended effect. The stabile consists of five triangular mountains of varying heights, the largest pierced with a circular hole, and two curving arcs, through which pedestrians can pass. The entire sculpture is painted flat black, as Calder wished, to contrast with the white marble of the atrium. From the floor, the massive mountains present an imposing view; the entire sculpture seems to change shape as the viewer moves to different locations and varied heights overlooking the atrium of the Hart Building. In 2016, the clouds were removed after completion of a structural safety analysis. They will be refabricated and installed as funding becomes available.

In August 1976, S. Res. 525 was passed designating the building the Philip A. Hart Senate Office Building. At the time, Hart was critically ill; he represented Michigan in the Senate from 1959 until his death in December 1976. An inscription inside the main entrance to the building on Second Street NE was added in 1986. It describes Hart's courage and integrity and concludes: "His humility and ethics earned him his place as the conscience of the Senate."