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My Best Use of Metal-September 2018

Plymouth1

Plymouth Place, Des Moines, Iowa

The existing historic, modern, cast-in-place building needed an entry canopy. We chose metal to tell a story of the tension structures. The entire building is a tree-like, steel-tension structure, but it appears to be load-bearing concrete. The canopy was our sculptural narrative.

The historic renovation of a mid-century modern building is a relatively new endeavor. Plymouth Place was not yet 50 years young, but had been deemed exceptionally significant by the National Park Service in the admittance letter to the National Historic Register. The team found the set of challenges familiar, but with new parameters and opportunities. The restoration of this building began by speaking to the original architect. In our discussions, the thing he most wanted to make clear was the building could have been truly beautiful if the owner had approved the scheme that was just four stories taller.

A very different parameter to this historic rehabilitation was the pallete of materials—concrete and glass. So many historic projects have window rehabilitations that are focused on wood profiles, but here the team was working to recreate aluminum windows. The original windows had lasted less than 15 years. The failures of the original windows were calamitous. The “space-age” material had been detailed in the smallest of profiles to accentuate the glass of the opening, but these small profiles failed in mass. The solution was a knee-jerk reaction to the failure of futuristic material—a clumsy infill of plywood and residential wood windows. For nearly 30 years the building was only appreciated because of its uncommon shape because the fenestration was a disastrous remedial fix.

The team located the original shop drawings for the windows and meticulously detailed the new windows to match the original profiles that had failed. Some profiles could not be duplicated, because they would again fail, but, in the end, the windows were within 1/4-inch of the original design intent. The renovation even included the aluminum grilles used for the original window air conditioning units.

Other project inclusions were making many units accessible, combining units to create larger, more marketable units, and an era-sensitive upgrade to wall finishes and furnishings. The only addition to the building was a canopy. The elderly residents needed a cover from the drop off to the door. A hunter green canvas barrel vault had functioned as protection, until a wind removed it a few months prior to the project start.

The new canopy was to reflect the era, respect the building, but not look like an original fixture. The design introduced steel rather than concrete, but paid homage to the building by being tension dependent, as the building is in a serendipitous way. The building floors are supported by tension steel from a large concrete beam at the top of the building. It is this tension that supports the cantilever of the building and allows the base to be window dominant rather than structure dominant. The canopy uses steel and tension to show lightness and flight, rather than hide the tension, as the building had done for five decades.


Brent A. Schipper, AIA, LEED AP, principal, ASK Studio, Des Moines