Central City Concern had a unique challenge in implementing a seismic retrofit and systems upgrade to the Henry building, an un-reinforced masonry (URM) structure containing 153 units of deeply affordable housing in downtown Portland. Given the building is listed on the National Register of Historic Places, the retrofit strategy had to be executed without impacting the exterior façade, the appearance of the interior daylight atrium, or many of the interior features with historic significance.
SERA’s design solution added four concrete cores which act as the primary vertical elements of the seismic structural system while also serving as elevator shafts for the residential floors. The proposed design solution provides the seismic strengthening and systems insertion needed, is cost efficient, and offers the feasibility of an occupied renovation by phasing the construction work by floor through a carefully-outlined moving and relocation plan.
Features designed to reduce energy and water utilization, as well as the implementation of a rooftop solar PV system, contribute to the long-term financial viability of the building.