The Irwin Conference Center (also known as the Irwin Office Building and Conference Center; formerly known as the Irwin Union Bank Building) is a commercial building at 500 Washington Street, on the northwest corner of Washington and Fifth streets, in Columbus, Indiana, United States. The modern-styled building was constructed as the Irwin Union Bank's downtown Columbus branch. Eero Saarinen designed the one-story main building and the original three-story office wing in the early 1950s. His associates Kevin Roche and John Dinkeloo of the firm Roche-Dinkeloo were responsible for a three-story office annex in the 1970s, along with a drive-through facility on the grounds. The landscape architect Dan Kiley added a lawn and trees. The building has received critical acclaim for its design over the years, and it was designated as a National Historic Landmark in 2000 for its architectural significance.
The main building, at the street corner, has a square floor plan with a glass facade and a concrete roof with nine shallow domes. The original office wing, north of the banking hall, is set back behind another building and has a brick-and-concrete facade and windows. A steel-and-glass arcade leads westward to the annex, which is made of similar materials. Inside, the first floor of the main building is an open plan space with tellers' counters, a conference area, and furniture. A staircase descends to a basement that originally included a kitchen, dining area, vaults, and offices. The office wing and annex contain additional offices.
The idea for the bank came from J. Irwin Miller, the president of the Irwin Union Trust Company (later the Irwin Union Bank) and a major architectural patron. He commissioned Saarinen to design a new building for the bank in 1950, and Irwin Union Trust acquired the site the next year. Although construction began in 1953, most work did not take place until the following year. The building opened on March 10, 1955. The design helped increase business at the Irwin Union Bank, and the bank decided to expand the building in 1970; the annex was completed in 1973. The bank acquired further properties nearby in the late 1980s and early 2000s. Due to the 2008 financial crisis, the Irwin Union Bank went into receivership in 2009. Afterward, the building was acquired by the First Financial Bank, which sold it the next year to the conglomerate Cummins. The bank building operated as a conference center and office building until 2020; it has been closed since.
Site The Irwin Union Bank Building (also the Irwin Office Building and Conference Center) is located at 500 Washington Street in Columbus, a city in Bartholomew County, Indiana, United States. It is set back from the northwest corner of Fifth and Washington streets, which, at the time of the bank's construction, was the town's busiest intersection. Adjoining the Irwin Union Bank Building are commercial buildings, which rise two or three stories. The Irwin Union Bank Building's previous headquarters, a limestone building, was across the street. The Irwin Conference Center is one of several contemporary-style buildings on Fifth Street in downtown Columbus, along with the Cummins Corporate Office Building, Cleo Rogers Memorial Library, and First Christian Church. It is also close to other structures such as The Republic Newspaper Office and Columbus City Hall.
Landscape As built, the bank building occupied only one-third of the site. The rear or western portion houses a drive-through window and a large parking lot with trees. When the bank building was erected, the Irwin Union Bank did not own the entire site, and part of what is now the parking lot was occupied by another structure. Dan Kiley, the bank building's landscape architect, selected specific types of trees and foliage to provide shade and integrate the building into the streetscape. He used littleleaf linden trees as the basis of the space, with euonymus as ground cover and seasonal spring bulbs, begonias, geraniums, and chrysanthemums as accents. Kiley also added an underground sprinkler system to irrigate the plants. These plantings created a park-like feeling, as the Irwin Union Bank Building is shorter than the structures around it.
The main bank building is set back from the sidewalk. Trees are also placed around the bank building, which, according to the Architectural Forum, was intended to attract passersby. Originally, there were 27 sweet gum trees surrounding the main building, each measuring tall. The trees stand near the sidewalk, helping to integrate the building into the streetscape, since the adjacent buildings are not recessed from the sidewalk. The original trees were saplings; they were intended to obscure the neighboring buildings as they grew, thereby reinforcing the building's park-like feeling. West of the building, the trees are planted in three rows spaced apart; some of the original linden trees have been replaced with honey locusts. There is also a lawn west of the original bank, surrounded by honey locusts.
The original plans included an early iteration of a drive-through teller's window, located west of the main building, with a driveway and parking lot for customers who did not want to go inside. A driveway, dating from 1966, travels between the trees and splits into multiple lanes divided by brick and concrete median strips. The driveway is paved in concrete aggregate with brick-paved borders, and there are steel and aluminum bollards illuminating the driveway. Within the driveway are three standalone bank teller booths, also added in the 1966 renovation; they have canopies designed in the 1980s by Frank Adams, a local architect. When the building was constructed, there were radiant heating coils embedded into the outdoor concrete slabs.
Architecture The Irwin Office Building and Conference Center was designed in two phases. The original one-story bank and a small three-story office wing were designed by Eero Saarinen in 1954. The office wing conceals the irregular northern boundary of the lot, where a former railroad's right-of-way cuts diagonally across the lot's northeast corner. Although the railroad had stopped running by World War II, Saarinen's building occupies part of the line's right-of-way, and an adjacent alleyway follows the railroad's path. To the west of the main building and office wing is a three-story office annex added in 1973 by Kevin Roche and John Dinkeloo, both of Roche-Dinkeloo (a successor firm to Saarinen's practice). The Roche-Dinkeloo annex extends westward through the block. The writer Matt Shaw stated that the design combined the clean lines of Miesian buildings and the welcoming atmosphere of modernist buildings designed at the Cranbrook Academy of Art, where Saarinen had studied.
The Irwin Union Bank Building is one of seven buildings in Columbus designated National Historic Landmarks. The others are The Republic Newspaper Office, the Mabel McDowell Adult Education Center, the Miller House, the North Christian Church, the First Christian Church, and the First Baptist Church. Of these buildings, the Irwin Conference Center is one of three designed by Saarinen, the others being the Miller House and North Christian Church; all three buildings were commissioned by the local businessman J. Irwin Miller. The bank building is also one of several modernist public buildings that Miller commissioned in the town, and, along with a 1952 cottage in Canada, one of four buildings that Saarinen designed for Miller. The annex is also one of several Roche-Dinkeloo designs in Columbus, along with the city's post office and visitor center, as well as Cummins Inc. facilities such as the Cummins Corporate Office Building.
Exterior
Main building The main bank building is one story high and has a square floor plan measuring on each side. All four elevations of the facade are divided vertically into 12 bays of glazed panels with steel frames. On each elevation, the lowest of the facade consists of Indiana limestone, while above it are windows that extend to the roof. Each bay has a horizontal steel mullion bar, dividing it into two panes; the lower pane measures high, and the upper pane spans most of the bay's height. The facade's steel framework is made of mullions measuring thick, which protrude from the glass panes. Each corner of the building consists of two protruding, perpendicular mullions, creating a hollow corner on the outside. The glass-walled design was intended to contrast both with traditional banks' facades and with the office wing to the north. The trees around the building provided shade for the glass walls.
The western elevation has drive-through tellers' windows; there are two, each with bulletproof glass, though their function was later supplanted by three standalone booths. The building is accessed from a heated vestibule at the southern end of the eastern elevation, which leads to Washington Street. The main building's northern elevation has a pair of glass-and-steel passageways leading to the southern side of the office wing, which lead west into an arcade in the 1973 annex. Sweet gum trees were originally planted in the courtyard between the two passageways. The tellers' windows, entrance, and passageways have similar glazing to the rest of the facade, but are about high.
The building has a concrete roof clad in standing seam metal. The roof's thick concrete slab is above ground level. At the perimeter of the roof, eaves extend beyond the facade; the eaves are angled downward, doubling as a coping. Within the roof are nine small domes, each of which is a thin-shell concrete vault. The domes divide the interior into a 3×3 grid of square bays. They were intended to give a sculptural quality to the roof, which is otherwise flat, and they also served to reduce the dead load of the roof, making it lighter. In addition, the domes allowed rainwater to flow off the roof.
Office wing and annex
The original office wing is set back behind another building on Washington Street. The office wing largely measures east–west and north–south; due to the presence of the alleyway at the northeastern corner, the eastern elevation narrows to . It appears as a separate structure, since it shares no common materials or shapes with the main building. The office wing's south elevation has a glazed-brick facade with several openings; the northern elevation is made of concrete block with steel-framed windows embedded into it. The other two elevations are attached to other buildings: the northeastern and eastern elevations are party walls shared with the Washington Street building, and the western elevation is shared with Roche's later annex.
Roche's annex is connected to the original wing via an arcade, which has brown-brick floor pavers. The annex is three stories high and uses similar materials to the original office wing. The western and eastern elevations have masonry walls. On the northern elevation is a , steel-and-glass frame that includes air-conditioning ducts. The steel-and-glass frame encloses a patio running the building's length. A similar frame encloses the arcade on the southern elevation, although this frame has alternating bands of reflective and clear glass strips; the upper part of the arcade's frame slopes down at an angle. On both the northern and southern elevations, the steel strips function as mullions. Dan Kiley oversaw the landscape design for the arcade, adding tropical plants such as bougainvillea.
Interior