8 NW 8th

Unique Housing Project Emerging in Pearl

by Brian Libby

Central City Concern has long been one of Portland's most ambitious builders of affordable housing, renovating numerous structures for the under-privileged-mostly older buildings converted for single-room occupancy. But until recently, the organization had never spearheaded a building project from the ground up.

Builders and designers of 8 NW 8th, near Portland's Pearl District, used a number of methods to ensure the longevity of the structure. Rendering courtesy of SERA

Enter 8 NW 8th, Central City Concern's first new housing project. Its location would entice even high-end apartment buyers, situated along Portland's North Park Blocks, just across Burnside Street from downtown and within a few blocks of the burgeoning and chic Pearl District.

The project got off to a difficult start, with SERA Architects taking over for another architect after the project could not get through local design review. But 8 NW 8th is now on budget and on time for a summer completion.

Although it will not seek LEED certification from the U.S. Green Building Council, the design and construction by SERA and Walsh Construction, respectively, shows there are different ways to define what is sustainable. The team likes to use the phrase "hundred-year building" to describe the project, for it is intended to withstand the wear and tear that most buildings succumb to in just a few decades.

"Throughout the whole process we've been looking at longevity of materials, which isn't something that LEED gets into," says lead architect Paul Jeffries of SERA. "We've got our own approach."

That durability began with an unconventional approach to the exterior skin of the building. Instead of using a concrete metal stud framing with fiberglass bat insulation going into the stud wall cavity, Walsh instead convinced SERA and Central City to let them take the fiberglass bat insulation out of the stud cavity and put rigid insulation on the exterior sheathing as well as the exterior waterproofing membrane.

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Not only does this prevent heat loss through the thermal bridge created in the stud wall cavity, "It puts the dew point outside the waterproofing membrane, and it put it in a drainage panel, which is where it should be," explains Walsh's Dean Lindstrom. "Since the rigid insulation is outside and not touching the outboard of the metal studs, then the whole thermal bridging of the metal studs becomes a non-factor." That means a much-improved performance through less transfer of heat and cool. Although this type of wall system is often used in Canada, it's a fairly new practice in Portland. But Walsh hopes to make it commonplace in the future.

8 NW 8th also includes a number of more familiar green features: a heat recovery system, CO2 sensors, low-flow shower heads and faucets, high-efficiency appliances, occupancy sensors, and compact fluorescent lights. These will reap energy savings of well over $25,000 per year.

Lindstrom credits SERA for incorporating these green features into the construction specifications, "so it wasn't something that the general contractor on bid day had to figure out by himself," he said. "Once a set of specs and plans is done and the subcontractors and everybody bid on it, they'd be bidding on the green systems and processes because they were already part of the job. It never used to be that way."

The project is also noteworthy for having just seven columns despite its 12 stories. Instead, much of the structural support comes from its shear walls. This brings added flexibility to the design, which had a mandate of mixing single-room-occupancy residences with larger studios above. Jeffries estimates the minimization of columns will also save about $200,000.

This design originality can also be seen in other details throughout the building, such as the curving two-story glass wall comprising the first two floors or the correspondingly rounded roof form.

"We're doing a modern interpretation of the classical form," Jeffries notes. "The building follows certain rules and bends others. We wanted it to be familiar enough for people to feel comfortable, but we also wanted there to be some double takes."

Indeed, this precisely the type of building at which Portland seems to excel: sustainable, handsome without being showy, and a seamless addition to a much-admired urban fabric.

Project Team:

Owner: Central City Concern
General Contractor: Walsh Construction Co.
Architect: SERA Architects

Useful Sites:

• www.centralcityconcern.org