(CS1.4) Rehabilitating Two National Historic Landmarks: Preservation Brief #16 and the Search for Exterior Materials that Outperform Wood

The Heritage Project involves the rehabilitation of the first two academic buildings constructed by the University of Oregon. University Hall (1877) and Villard Hall (1886) are National Historic Landmark structures that embody the origin story of UO and public higher education in Oregon.
The Second Empire style buildings incorporated wood in many forms - cedar roof shingles (common and scalloped) and an array of decorative wood columns, urns, plant forms, shields, armillaries, balustrades, and paneled parapets. The decorative elements were originally coated in a lead, sand, and paint mixture to simulated stone. Not surprisingly, the coating was short-lived and all the decorative wood elements on both buildings were missing or had been replaced, some multiple times, over the past 140 years. This was destined to be the case because in Oregon’s climate - wood is food.
Our team’s process for identifying and vetting substitute materials was, in part, guided by the recently updated version of Preservation Briefs #16: The Use of Substitute Materials on Historic Building Exteriors. Of the eight categories listed in the Brief, three were directly applicable for the Heritage project: Inadequate durability of the original material, Reconstruction of a missing feature, and Enhanced resilience and sustainability.
Evaluation Criteria:
Our list of evaluation criteria is based on PB #16’s list, along with several additions, and includes life span, record of performance, physical properties/visual appearance, maintenance, sustainability, cost, weight, vendor experience, availability/schedule, and warranties. For the dozens of unique decorative wood pieces, we investigated and prioritized materials with an estimated life span of approximately 50 years, are durable and easy to maintain, and provide sustainable benefits.
The list of substitute materials studied includes wood as a base condition (original species of Douglas Fir/Western Red Cedar and alternate wood species, such as ipe), cast metal, sheet metal, Glass Fiber Reinforced Concrete (GFRC), Glass Fiber Reinforced Polymer (GFRP), and Sign Foam.
Based on our findings, project logistics, schedule, and construction budget - the treatment recommendations included a combination of substitute exterior materials. This presentation will share our process, research, reasoning, and relative cost of the substitute exterior materials we studied and specified.