The Internal Revenue Service Building is located in the center of the Federal Triangle complex in Washington, D.C. It is bounded on the north by Pennsylvania Avenue, and the west by 12th Street. The IRS Building is rectangular in form with a circular section on its northwest corner facing 12th Street and an L-shaped arm from the northwest corner on 10th Street. The main building has 4 interior courts which divide the great mass of the building and provide the inner offices with daylight and ventilation. The building is 7 stories in height, although the architectural treatment of the exterior walls gives the illusion of 5 stories. Th 6th floor is located behind the main cornice and the 7th floor is set back behind the balustrade. The general architectural style for the Federal Triangle was the 18th century French Renaissance style, which in turn derived its inspriation from the Italian Renaissance architecture. The IRS Building is one of the more simple interpretations of this style in the Federal Triangle.

The Constitution Avenue facade contains the main entrance to the IRS Building and received the most elaborate decorative treatment of all the building's elevations. The remaining facades have the same general characteristics as the Constitution Avenue elevation, which has a rusticated limestone base of 14 courses extending from the pink granite base course or stair at ground level through the second floor to form the first horizontal division. Above the first floor windows, the rusticated design resembles a jack arch with the three central keystones extending vertically through two courses. The Constitution Avenue elevation is 27 bays wide. All except the first and last three bays of the base project approximately 4 feet from the building plane.

The upper floors are dominated by a 3-story colonnade which extends above the projecting base. Above the 3rd floor belt course, a balustrade motif defines the beginning of the principal stories. On the colonnade, a balustrade separates the column bases. The wall surface is smooth faced limestone ashlar. Rusticated limestone, more finely detailed than the base of the wall, serves as quoining on either end of the elevation, and faces the wall surface behind the colonnade. Pilasters shadow the pairs of columns at either end of the colonnade. The facade is capped by a Corinthian entablature, which begins at the 6th floor level. This is composed of 3 horizontal divisions. Another balustrade with paneled piers sits atop the facade at the 7th floor level.

The 10th Street elevation is the longest of the building, extending over 600' from Constitution to Pennsylvania Avenue. Two pedimented prostyle porticos of 3 bays each mark each end of the elevation. The south portico has four marble columns, the north portico has 4 limestone columns. Two end pilasters, identical to those on Constitution Avenue, mark the sides of each of the porticos on the facade wall. Centered in the 10th Street elevation is a major entrance with a single wide stair and three flat arched openings. Above this central entrance, beginning at the 3rd floor level, is a screen of 18 limestone, unfluted pilasters of the Doric order. A street level arcade with 3 arched openings approximately 1-1/2 stories high is centered between the projecting central bays and the north portico. Balustrades matching those at the 7th floor level extend across the bottoms of the openings.

On the Pennsylvania Avenue facade, the 5 bays nearest the corner of 10th Street and Pennsylvania Avenue are idential to the unpilastered bays on 10th Street. The remaining six bays project several feet and have a screen of eight limestone pilasters similar to those on 10th Street.

The 14 bays on the south eand of the 12th Street facade repeats the basic wall design established on the Constitution Avenue facade. Small one story entrances are located on the second bay in from each end. Because the circular elevation on the northwest corner of the 12th Street facade was to form part of the Great Circle with the New Post Office (Ariel Rios) Building across the street, its decorative details mirror those of the other Federal building. The circular elevation has a 3-sided pavilion at its corner, directly opposite the south pavilion of the New Post Office. The decorative details on both are identical.

The interior spaces of the IRS Building are organized around four courtyards with office bays located on either side of a central corridor. With this arrangement, all offices are provided with operable windows, facing the streets or the courts. The most elaborate space in the building is the 2 story lobby in the center of the south side of the building. The original design of this space remains intact. Most of the office corridors retain their original terrazzo floors with brass dividing strips and marble borders, marble baseboards and plinth blocks. All the special offices in the IRS Building, the Tax Court Hearing Rooms, the Commissioner's office and the 7th floor Court Room have undergone remodeling. General office space is typical and has also undergone remodeling.

The Internal Revenue Service Building, built between 1928 and 1936, was the first building to be constructed within the Federal Triangle. The Federal Triangle project was the largest building program ever undertaken by the government; it was the first federally funded urban redevelopment project of this scope and, as such, provided a model for city planning in the 1930's through 1950's. The new buildings were to be designed to reflect the "dignity and power of the nation". Senator James McMillan introduced legislation in 1900 authorizing plans for developing an urban park system and for the siting of future Federal buildings. McMillan's plan proposed that the triangular area south of Pennsylvania Avenue, north of the mall and east of the Ellipse be developed for Federal office buildings and museums. The plan for the Federal Triangle was tied to the passage of the Public Buildings Act of 1926 and, finally, in January, 1928 the Triangle Bill was passed authorizing acquisition of land and allocating funds. There is correspondence to indicate that there was a plan drawn for this building as early as 1926, before the master plan for the Federal Triangle was formulated. According to the "Unified Architectural Composition Plan" publicized by the Commission of Fine Arts in July 1927, IRS was to form half of a "Great Circle" measuring 500' in diameter at the intersection of 12th Street and the former C Street. Because the IRS Building was to be used as a bureau and not as a departmental headquarters, originally planned sculptural bronzes and stonework were not included, therefore separating the unadorned IRS Building from its neighbors in appearance.

The IRS was founded in 1872 but was a minor section of the Treasury Department until the income tax law was passed in 1913; by the 1920's the IRS had 6000 employees housed in temporary wood frame structures generally considered "fire traps"; the need for permanent headquarters was generally recognized not only because of the appalling working conditiions but because of the constant threat of fire to the tax records. A month after the Public Building Act was signed the decision was made to proceed as soon as possible with IRS and the Department of Commerce due to the threatening conditions. The building was first occupied June 1, 1930 having been completed 16 months ahead of schedule (the contractor received a $30,000 bonus for early completion). The building was equipped with a synchronized system of 861 clocks, the largest system of its kind at the time of construction. In addition to being synchronized the system had a conduit system related to the fire alarm and the watchman's system. 1400 telephones were installed.

When the 18th Amendment (Prohibition) was repealed in 1933, the work of the IRS increased sharply and more office space was needed. An extension was begun (the northeast sections) in February 1934. The general form and exterior appearance of the extension duplicated the exterior detailing of the main building and completed the symmetry of the facade.

It was intended that the IRS Building be completed on the site of the 19th century Post Office building but plans were delayed for social, political and economic reasons until the late 1960's when proposals were made to complete the Federal Triangle. By this time the Urban Renewal program (initiated by the concept of the Federal Triangle) was in full practice and public outcry against the destruction of historic properties was beginning. The preservation movement in Washington took as its first major issue the demolition of the Old Post Office. A struggle ensued between Federal plans and citizens' groups. The 1966 Historic Preservation Act provided a legislative boost to the citizens groups and the group, named "Don't Tear It Down" was able to save the Old Post Office building. The IRS Building, therefore, was never "completed" and the look of the Federal Triangle was adapted to include the 19th century Post Office Building.

The Internal Service Building is a component of the Pennsylvania Avenue National Historic Site (National Register #66000865).

Year
Start
Year
End
Description Architect
1928 1936 Original Construction Louis Simon
1935 Installed limestone ceiling in 12th St. arcade unknown
1947 5 ton a/c unit added to rooms 1515-1533 unknown
1954 Asphalt tile laid over flooring, rooms 1002-1016 unknown
1954 Rooms between 3309-3319 converted to lecture room unknown
1963 Central air conditioning system installed unknown
1963 Suspended ceilings added to conceal a/c ducts unknown
1963 Fluorescent fixtures installed unknown
1964 2nd floor judge's quarters renovated unknown
1964 Commissioner's office suite modernized unknown
1965 1967 Toilets renovated unknown
1966 Chief Counsel's library built on 4th floor unknown
1968 Visitor's center built in middle of main lobby unknown
1969 Computer center installed on 6th floor unknown
1972 New auditorium replaced old court room, 7th floor unknown
1974 Elevators switched from manual to automatic unknown
1974 Visitor's center structure removed; lobby restored unknown