Great Glazing: Slate

Slate building facade

Photos by Joshua Jay Elliott, courtesy of Works Progress Architecture and Wausau Window and Wall Systems.

Slate building facadeThe basics: The new 10-story, mixed-use, transit-oriented development, known as Slate, in Portland, Oregon, is a cornerstone in the city's efforts to revitalize the Burnside Bridgehead area. Opened in September 2016, the project spans 147,000 square feet and offers 75 market-rate apartment units on the upper six floors, 35,000 square feet of creative co-working office workspace and 7,800 square feet of retail space at street level. Slate's design features floor-to-ceiling curtain wall that maximizes views of the downtown, the Willamette River and Mount Hood. The glass, metal and concrete façade consists of articulated, modulated, rectangular shapes, including some that are set back and some that project over the sidewalks below, creating the illusion of a shifting stack. The curtain wall, which modulates from flat on two sides of the building, to textural on its other sides, is crucial to the building’s design.

The players: Architect, Works Progress Architecture; general contractor, Yorke & Curtis Inc.; contract glazier, Dallas Glass; glass manufacturer, Vitro Architectural Glass; metal systems supplier, Wausau Window and Wall Systems (curtainwall), Firestone Building Products Co. (metal panel inserts), Linetec (aluminum framing and panels finishing)

The glass and systems: The high energy-efficiency building features window, entrance and unitized curtain wall systems by Wausau Window and Wall Systems, which provided more than 40,000 square feet of INvision 7250i-HRX SSG Series unitized curtain wall and 7250 Series SuperWall, along with 240 project-out awning 4250Z zero sightline windows, 4250i-TD Series terrace doors and D5100 Series sliding patio doors.

To match Portland's climate and the project's goals for energy efficiency and occupant comfort, Wausau's aluminum-framed products have been thermally improved by Linetec using a polyamide barrier. Combining the thermal barrier with solar-control, low-e, insulating glass from Vitro Architectural Glass achieves the specified performance for low solar heat gain coefficient, low U-Factor, high condensation resistance factor and high visible light transmittance.

Seasonal opportunities for natural ventilation also help reduce the demand on HVAC systems and associated energy use. Weather permitting, the operable windows on Slate allow tenants to enjoy fresh air, natural light and views.

This project was the glazing contractor's first experience with a unitized curtain wall system. "We loved it," says Darand Davies, president of Dallas Glass. "It was rather amazing that, on average, we have just five guys in field who were capable of completing a full floor every two weeks."

Linetec finished the frames on Wausau’s products, as well as the matching aluminum panels supplied by Firestone, in a Dark Bronze anodize.