Property Type: Institutional
Neighborhood: Downtown  |  County: Ada  |  Building Status: Public  |  Year Built: 1938  |  Architectural Style: Art Deco- Streamline Moderne
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The Capitol Annex building, otherwise known as the historic Ada County Courthouse, sits just east of the Idaho State Capitol and was built in 1938-1939 as part of the Public Works Administration during the Depression.

It is a 9 story building, originally with offices on the lower floors, courtrooms on the 3rd floor and jail cells in the upper floors. The exterior is Indiana limestone and scored concrete. It was built in a Streamline Moderne style ? a stripped down version of Art Deco ? with geometric shapes and strong lines, ideal for governmental buildings, symbolizing strength and stability. The lobby floors and wall wainscot is pink Tennessee marble and the moldings in the corridors are hand crafted woodwork.
The PWA used Indiana limestone to cover the first four floors of the building. This is unique as it is the only structure in Idaho to have this particular type of material, when most local buildings utilized the less costly local Boise sandstone. However, the top floors were constructed simply of scored concrete.

The Old Ada County Courthouse is one of Boise’s more interesting buildings with a distinct history and style. Placed on the National Register of Historic Places in 1974, the courthouse had been used for about 63 years as a courthouse, jail, and legislative office building. Designers “Wayland and Fennell” (W&F) worked in conjunction with the architecture firm of Tourtellotte and Hummel (T&E) laying out the blueprint and ideas. Evidently, T&E suggested a more classical design and W&F proposed the Art Deco style which became the plan.

Following the Egyptian rage from the discovery of King Tutankhamun in 1922, Art Deco mimics the ziggurat frames of pyramids. Another characteristic is the mimicking of movement. The repeating vertical lines create a sense of upward flow, making the building seem larger than it actually is. To add to the vertical perception of this building, small towers run along the length of the building as well as on the top. The staggering of many of the geometric shapes accentuates the flow of the building because of the rhythmic changes.

The building of the courthouse was done by the Public Works Administration (PWA) and was part of the local efforts at work relief during President Roosevelt’s New Deal in response to the Great Depression.

The state leased the building to provide office space for state legislators when they were in session. It soon became apparent that space was limited, and the legislators made several proposals to renovate or rebuild the courthouse. When destruction loomed near, Boise locals protested and the fate of the courthouse fell into stalemate. On February 1, 2002, the courthouse was officially abandoned.

The interior is simple, architecturally, but the building’s greatest asset is inside. Originally designed with each panel representing a legend in Idaho history,created by Ivan Bartlett from California to depict Idaho legal history, including a mural depicting a lynching of a Native American that is currently veiled.
Critics were quick to notice the boy with three arms, the horse with no tongue, as well.

Also see Preservation Idaho’s great collection on the Courthouse at

In 2010 the University of Idaho expressed interest in leasing the building to be the future home of the law program, and extensive renovations took place by LKV Architects over the next five years, opening to the public in 2015.

A complete infrastructure update involved demolition of multiple remodels that had happened over the years, preserving the history of the building and landscape while bringing the building up to code and for a useful new life by the U of I.

Preservation Idaho is so glad to honor this important building, the State of Idaho Department of Administration, Division of Public Works, LKV Architects, and the Idaho Law and Justice Learning Center with a 2016 Orchid Award for Contribution to Historic Preservation.

Accepting the award at the 39th Annual Orchids and Onions Award Luncheon was Brook Thornton of LKV Architects.