The Mississippi Building

KPFF provided civil and structural engineering design for this new 9,550 SF mass timber building comprised of six equal rooms, stacked in three tiers on each side of a shared courtyard. The all-wood structure is mixed-use, with retail on the ground floor, offices on the second floor, and residential units on the top floor.

Mississippi is the first commercial project in Oregon to use mass timber construction for all components of the building. The exterior of the building is wrapped with weathering steel for weatherproofing protection and the interior is made up of only exposed mass timber with the exception of the non-structural radiant concrete flooring. Roof and floor framing consists of CLT3 and CLT5 panels with glulam beams spanning to the CLT5 shear walls. The stair is also composed of entirely CLT panels with glulam treads.

Civil design included: sidewalk design and internal courtyard grading; drainage plans including an onsite infiltration facility; utility connections for water, sanitary sewer and storm drainage; erosion control; and stormwater.

The building is the basis for the Wood Innovations Grant project led by Waechter Architecture. This project explores alternate typologies of all-mass timber buildings and compares those to typical hybrid construction types with mass timber.