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Portland’s Bureau of Development Services recently issued building permits for an eight-story, mixed-use development in the outskirts of the Gateway Plan District.

TimberView, previously named Glisan Tower, will provide 105 affordable housing units and a ground-floor food hall with four vendor spots. Apartments will be offered to people earning 60 percent of the area median income or less.

Access Architecture designed the project at 9919 N.E. Glisan St. Truebeck Construction is the general contractor.

The new name more adequately describes 鈥渨hat we are doing,鈥� said Curtis Rystadt, the project’s developer. TimberView will have a mass-timber frame with glulam columns and beams and cross-laminated timber (CLT) floor panels. It will be the tallest CLT affordable housing development in Portland (possibly in Oregon), according to Access Architecture principal Brendan Sanchez.

The project is Access Architecture’s first to feature mass timber. Affordable housing developments like this one typically use 鈥渇ive-over-two鈥� construction featuring concrete and light wood framing, Sanchez said. However, Rystadt wanted all timber, he said.

鈥淲hen you look at building materials and their effect on the planet, steel and concrete are much more disruptive than wood,鈥� he added. 鈥淲ood is the best building material that we have.鈥�

Portland permitting

TimberView landed in the new, sparsely navigated waters of Type IV building classification. A statewide alternate method (SAM) for CLT 鈥� the first in the country 鈥� was introduced in 2018 and further adopted into the Oregon Structural Specialty Code (OSSC)聽a year later.

Only a handful of projects in Portland, including Central Lofts and the Chiles House, have been permitted under the Type IV C classification that allows a timber building up to nine stories (85 feet) to leave all the structure exposed as interior finishes. Only one other building as tall as eight stories, Minnesota Places (a mass-plywood-panel affordable housing development), has been permitted under it in Portland.

In fact, the most recent eight-story CLT project to receive building permits in Portland was Carbon 12. It became a catalyst for new building classifications.

On track to be the nation’s tallest timber building at the time, Carbon 12 had to go through a special permitting process that involved the state looking at the structural and fire and life safety aspects and the city of Portland reviewing the nonstructural components.

The only other mass-timber project taller than eight stories to receive building permits in Portland was Framework 鈥� a 12-story mixed-use development that was halted in 2018 due to escalating construction costs. The project team, however, has a redemptive building on track 鈥� Sandy Pine.

Now, projects like TimberView can enter Portland’s building permit process like any standard building 鈥� though review is a bit different, particularly for the fire rating. Like Carbon 12, TimberView is using a char layer for its main fire rating. In an event of a fire an outer layer of wood is designed to char but leave the structural core untouched.

Kevin White, a structural engineer for the city of Portland, said he spends much of his time double-checking the char layer calculations submitted by projects’ engineering teams to confirm whether: a) the building’s loads can be supported as is, and b) in the event of a fire, the remaining non-charred sections of the structure can still support the loads.

All buildings with Type IV classification must have a minimum two-hour fire rating. The taller the timber building, the more there is a need to encapsulate the structural frame by a fire-resistant material like gypsum board or steel.

Rystadt initially wanted TimberView to be 11 stories, he said, but use of an all-timber frame above 85 feet would’ve required more materials to achieve the fire rating. That would’ve increased the project cost.

Timber expression

Keeping the Type IV C classification for TimberView was important, Sanchez said, because the team could then expose as much of the mass timber as it wanted.

鈥淥ne of the main drivers for the exterior concept was to express the structural frame of the building as well as the mass-timber components,鈥� he said.

The building’s main body is clad in metal panels, while the commercial spaces and residential entry on the ground floor have wood-panel siding and exposed timber. Along the south face toward Northeast Glisan Street, a timber line carves up the building to the eighth-floor amenity deck where the metal panels disappear to reveal the timber structure.

A similar effect occurs on the ground floor to reveal the glulam columns and create little nooks by the food hall at the corner of Glisan Street and 99th Avenue where people will be able to eat outside without feeling like they are in the street, Sanchez said.

TimberView will be the tallest building in the area, which includes other apartments buildings.

Truebeck Construction recently completed Chiles House, Portland’s first affordable housing project to be constructed entirely of CLT. That is a main reason why Truebeck was selected as general contractor, Sanchez said.

Innovative elements

In addition to mass timber, TimberView will have radiant floor heating; neither feature is typically included in affordable housing projects.

Rystadt, who grew up in the Pacific Northwest with radiant floor heating, said it always felt like a luxury to come in from the cold, take off his shoes and feel a warm floor. He wanted the same for TimberView residents, he said.

Currently, the project is on track to meet Leadership in Energy and Environmental Design platinum standards. The building will have extra exterior wall insulation, high-performance windows, and all-electric systems 鈥� and be solar-ready, Sanchez said.

鈥淚’d say the fact that we are trying to do multiple innovative design elements to this makes it more challenging,鈥� he said. 鈥淯sually, you try to do one or two innovative things per project, so you are not biting off more than you can chew.鈥�

With building permits issued, the project team is set to break ground soon.