Oakleigh Meadows Co-Housing: Multifamily Structural Engineering in Eugene, Oregon

Location: North Eugene, Oregon, beside the Willamette River
Client/Owner: Oakleigh Meadows Co-Housing
Partners: McCamant & Durrett Architects (architect); Foundation Engineering (geotechnical); Essex General Construction (general contractor)
Year: Structural design 2014; plan review support through 2016
Size/scale: 28 homes in seven two-story buildings of four types, plus a two-story common house
JBE services: Structural design of the seven residential buildings and the common house — gravity and lateral design, foundations, drawings, calculations and special inspection requirements; value engineering; plan review responses
Sector: Multifamily & Housing

Oakleigh Meadows co-housing structural engineering project, Eugene, Oregon — photo 2

The challenge

Oakleigh Meadows is a 28-home co-housing community in north Eugene, with homes in seven two-story buildings around a shared common house. The site sits a few hundred feet from the Willamette River, and part of it lies in the floodplain. The ground is silty clay and silt over gravel, and some of the buildings sit on imported fill. The site is in Seismic Design Category D, so every building needed a well-detailed lateral system — and the project had a tight budget.

Project photos

What we did

We designed the structure for all seven residential buildings, which share four building types, and for the common house. Each is wood-framed, with wood-panel shear walls and holdowns for wind and earthquake loads, engineered I-joist floors, glulam beams and slabs on grade. Repeating the building types let one set of framing plans and details serve several buildings.

We issued the permit set in July 2014. When the project needed to come down in cost, we went through the structure with the design and construction team and reissued the drawings as a value-engineered set that August. Working with the geotechnical engineer, we later replaced 18-inch footings with turned-down slab edges and 12-inch footings. We then answered the City of Eugene’s plan review comments on the revised set.

The result

The value-engineered structural design for a 28-home community and its common house was permitted with the City of Eugene, and it shows the kind of multifamily structural engineering in Eugene, Oregon that we do: repeatable, economical wood framing on a challenging riverside site.