ETHA Hotel Preserves Bozeman Armory Building

ETHA Hotel Preserves Bozeman Armory Building

BOZEMAN – With plans to break ground this fall, the 8-story ETHA Hotel reuses most of the Bozeman National Guard Armory Building originally completed in 1941.  The ETHA Hotel, also known as The Armory Hotel, is located at 24 West Mendenhall Street.

“The Armory was not built for military alone, but for community events and meeting as well.”  John C. Russell, “Life is Downtown,” July 9 2012.

The Armory Hotel Project is intended to yield a landmark addition to Bozeman’s historic downtown corridor, with an ambiance, style, and overall experience that is unique to Bozeman and the Northern Rockies region.  With upscale hotel features and amenities, unique dining venues focused on sophisticated, locally-themed menu offerings, and an impressive amount of quality event and flexible meeting space, the Armory Hotel Project will deliver a new dimension of experience to Bozeman’s vibrant and soulful center.

Kyle Dornberger,principal at VENUE Architects LLP, says the new downtown Bozeman landmark will be developed by rehabilitating and restoring the vast majority of the existing Armory structure as well as adding six stories within the existing footprint. The design concept is inspired by the original art deco style architecture of the building as well as the legacy of the original architect, Fred F. Willson – considered by most to be the patriarch of a unique, lasting architectural style that persists in Bozeman and various other Montana cities. With this model in mind, we intend to complement the original design intention of Mr. Willson with a modern interpretation of art deco that produces a warmer, cozier, and more welcoming feel that is a pure reflection of the authentic character of Bozeman. Balancing historical reverence with modern-day comfort, design appeal and functionality while delivering an authentically “Bozemanesque” experience are hallmarks of the design intention for the project. 

“Since no two problems are the same, the architect must visit the site, become intimately acquainted with the family or owner who is to occupy the structure. He must try to get himself into their way of thinking, living or operating. He must study their personality, mode of living, individual family requirements and provide a structure suitable for their needs. Few people realize the care and thought necessary to secure the maximum of usable space and still have an attractive interior and exterior. He must have knowledge of balance, proportion, scale and harmony. There is a fundamental reason for every feature embodied in a structure. It must have refinement, simplicity, beauty and good taste. Thus an architect’s business is to make the things of daily life beautiful.”

— Fred F. Willson, MSU Knowledge Quest, 1954

Site History

The Armory was built in 1941 as one of only six armories constructed in Montana. Featuring a drill floor, rifle range, enlisted and officer quarters, and reinforced steel concrete floor capable of accommodating military trucks, the Armory was formally dedicated just after the attack on Pearl Harbor and remained an active National Guard post until 2003.

The site of the Armory was donated by Nelson Story, III and his sister, Mayo Story Dean. The siblings dedicated the building in the honor of their parents, Nelson “Bud” Story, Jr. and his wife, Etha Mayo Story.

After its de-commissioning in 2003, the Armory was occupied only intermittently prior to the assumption of title by First Interstate Bank in 2011. In 2012, Etxea Hospitality purchased the Armory with the intention of adaptively reusing the structure in the development of a boutique hotel.

Project Summary

The adaptive re-use boutique hotel will feature 108 rooms, a 4,300 square foot Ball Room plus overlooking balconies, event rooms, a pool on the Level 3 Terrace with stunning views of the Bridger Mountains, a restaurant, a lounge, and a full-service spa. The total gross floor area exceeds 100,000 square feet.

The Art Deco style building also features many large steel canopies, and exposed steel seismic bracing that express the original architecture created by Fred Willson.

The Room Tower is a structural frame with special steel moment frames and eccentrically-braced frames to support seismic and wind loads.  The steel frame bears on precisely located foundation elements that are incorporated into the existing building’s foundation system.  “The foundation is a strategic design of cast-in-place concrete pads and strips supplemented with steel screw piles and concrete micropiles,” says Troy Leistiko, P.E., the structural engineer of record at Eclipse Engineering, Inc.  Several areas of the existing building foundation required undermining excavation, so temporary shoring was achieved with steel screw piles and steel support beams.  Undermined areas were ultimately re-supported with a lean-mix flowable concrete fill.

Structural engineering challenges included upgrading the existing cast-in-place concrete floors to support 2009 IBC level live loading for assembly areas, removing small portions of the existing concrete building for new access to balconies overlooking the Ball Room, and openings for stairs and elevator shafts.  The North Terrace is a large assembly area on the third level that features hot tubs and an expansive steel-framed patio supporting concrete pavers.

Special Steel Moment frames (north-south), and Eccentrically Braced Steel frames (east-west) support the lateral loads.  “Well thought-out detailing and careful coordination are the keys to ensure the steel will fit properly with minimal corrections,” says Chad Taylor, P.E., the design structural engineer from Eclipse Engineering, Inc.  Eclipse designed the lateral force resisting system with constructability and efficiency as a principal tenet. After an extensive study, Eclipse elected to employ the Bolted End-Plate prequalified beam-column connections in the special moment frames and also designed the concrete fill on steel deck floors to serve as collector elements in the diaphragm. These elements were included in lieu of using steel beams and the costly associated connections. Building Information Modeling added great value for the design team.  Eclipse employees explored linking their Revit and RISA analysis models early in design, though shortcomings in the process put a damper on the efforts as the project advanced.  Seismic joints are painstakingly placed throughout the building where the framing and floors for the new tower abuts to the existing concrete frame. The joints will ensure the bunker-like original building and the elegantly flexible tower are decoupled on the day Bozeman’s luck runs out and it is subjected to the design-level earthquake.

Nine-foot deep steel transfer trusses span 60 feet over the second floor Ballroom and carry the six hotel floors above plus the roof.  The typical framing is less exciting: conventional concrete fill on steel deck supported by composite wide-flange steel beams for the floors and steel deck on bar joists and castellated beams for the roof.

Exterior steel stairs, concrete stair wells to the below grade story, and the below-grade cast-in-place concrete fire-suppression tank complete the masculine feel of this structural masterpiece!

The project is a Construction Manager At-Risk Delivery Method with Martel Construction at the helm.  With a $13,000,000 construction budget, the hotel is slated to open to the public in 2015.


Chad Taylor, P.E., is a structural design engineer with Eclipse Engineering.


Troy Leistiko, P.E., is a principal structural engineer with Eclipse Engineering.


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