Project Description
Located in downtown Seattle, the 419 Occidental Ave. building needed to be redeveloped to fit the historic neighborhood’s shifting commercial landscape. While the building’s early 20th century architecture visually matched the surrounding designs, it would fail some necessary fire- and life-safety code requirements of modern architecture, such as having a fire-rated stairwell that met egress requirements.
SHED Architecture & Design decided to bring the stairwell to the building’s exterior and to flood it with natural light by specifying two transparent glass curtain wall systems on the east and west ends. While six stories of floor-to-ceiling glass is certainly eye-catching, the way the north and south ends balance design aesthetics and critical fire- and life-safety is equally impressive.
First, because the north end of the stairwell was both load-bearing and less than 10 feet from a neighboring building, it needed a 120-minute fire rating. Likewise, the south end of the stairwell had to incorporate fire-rated doors and windows to meet emergency egress code requirements. These requirements necessitated finding rated and non-rated assemblies that could create a cohesive design while also meeting daylighting goals.
The fire-rated products that join the building to the stairwell sport large lites of glass to connect the interior and exterior spaces visually and to let the light from the stairwell make its way into the building. This design also allowed the architectural team to include a fire-rated corner window system on the mezzanine level of the stairwell.
The window features floor-to-ceiling transparent glass held within fire-rated frames. Much like the expansive use of glass in the stairwell itself, it was essential this feature worked as specified and contributed to the building’s sense of uninhibitedness. Greg Shiffler, senior architect and partner at SHED, states, “The stair tower was one of the primary design moves on the project and it would not have worked without these glazing systems.”