CLIENT: Townsend, Inc.
INVESTMENT: $9,000,000
COMPLETED: Summer 2011
The Mercantile Bank & Trust Company Building (now Wall Street Tower) is a Modern 20-story high-rise on the southeast corner of Walnut & 11th Street in downtown Kansas City. With a construction date of 1974, it is not a typical historic building, but it is listed in the National Register of Historic Places.
The 20-story office tower was designed by the noted Chicago architectural firm Harry Weese and Associates, in collaboration with the Kansas City firm Patty Berkebile Nelson Associates. The Modern Movement design features an exposed steel structure that is unique in Kansas City. A 3-story base and a series of cruciform steel columns support a 16-story office tower above a retail plaza that is sunken below street level. An enormous structural “space transfer” truss forms the tapered bottom story of the tower and transfers the weight of the tower onto the columns and the base. The walls of the tower are formed by alternating bands of wide steel spandrels and ribbons of windows. By incorporating innovative fire protection features into the structural system, the designers eliminated the need for a veneer over the steel.
The building’s sculptural form illustrated the evolution of Modern architecture into the 1970s, as it moved away from the more typical slab building form. The sparse design was an economical, yet sophisticated, solution for a tight building lot in Kansas City’s dense commercial core. Contemporary writers praised the design for the “honest” expression of its sculptural form and anticipated that it would have a marked influence on future office building design. However, by the end of the decade inflation and the collapse of the American steel industry would make construction of similar buildings cost-prohibitive. The Mercantile Bank is the only example of this architectural genre in Kansas City and one of few examples in the country.
When the vacant office building was converted into condominiums beginning in 2005, the biggest hurdle with the rehabilitation was providing fresh air to each unit, as required by building code . The original glazing was fixed single panes held in gaskets between upper and lower structural steel spandrels. Getting fresh air into the buidling meant installing operable windows or a mechanical fresh air system.
An open window is hardly noticeable
Working closely with the National Park Service and the State Historic Preservation Office, Rosin Preservation helped the owners identify an operable window that would provide the fresh air and pass historic muster. The majority of this window frame is inside the opening, with external elements limited to gaskets around the glass that match the dimensions of the original window gaskets. Because the glass (original and new) is tinted, the window frame is not visible from outside the building. It was a win for the owner, the residents, and the historic building.