Location:12 South 6th Street, Minneapolis, MN
Client: Gerard L. Cafesjian, owner
Project Date: 2013
Project Scope: Research and Historic Consulting
At the time of its construction, the Plymouth Building was claimed by the reinforcement manufacturer and local newspapers to be the "world's largest all-reinforced concrete office building." When the building's owners first sought to have it listed in the National Register of Historic Places (NRHP), it was dismissed as ineligible and generally considered insignificant except for its size. If the building is not eligible for the NRHP, it cannot qualify for financial incentives, like the state and federal rehabilitation tax credits that would make building improvements and redevelopment possible.
Preservation Design Works (PVN) was retained by the owner to do additional research to determine if the building is historically significant. PVN’s research suggested that the Plymouth Building is eligible for the NRHP because it demonstrates “a type, period, or method of construction,” which is significant to American engineering. While the Plymouth Building is not associated with one obvious engineering event or patented system, the building is important for its reinforced concrete design and construction - especially the use of a reinforced concrete skeleton frame and deformed steel reinforcement, successful cold weather concreting, and an integrated builder-engineer delivery model. The Minnesota State Historic Preservation Office and the National Park Service approved the Part 1 application, and the Plymouth Building is now listed in the National Register of Historic Places. Eligibility for the NRHP allows the building to access the Federal Historic Preservation Tax Incentives and Minnesota Historic Structure Rehabilitation State Tax Credits. The federal tax credits can be up to 20% of qualified rehabilitation expenditures; likewise, the Minnesota state tax credits can provide an additional 20%. It is qualified for redevelopment.
Engineering and construction history are still relatively undeveloped areas of scholarship. Early larger structures such as the Plymouth Building demanded specialized engineering and design skills. These same structures can be adaptively reused today, however, accessing preservation-related financial sources is often needed to make these projects viable. At PVN, we specialize in this area of research, and bring unique historical research and analysis to buildings that might otherwise be “insignificant.”