What many desirable, expensive cities lack is an architecturally rigorous housing type that slots in between dense multifamily and single-family-detached. We used to build these kinds of dwellings—duplexes, triplexes, and so on—but it has become a lost cause and a lost art. This is where Seattle-based Hybrid Architecture comes in. Led by Robert Humble, the firm has been working this missing middle for more than a decade, blending strong design, livability, and community engagement with greater affordability. The firm isn’t named Hybrid for nothing.
The Steel Stacks four-plex is the latest example of the ingenuity Hybrid brings to underdeveloped or missing-tooth lots in the city, in this case a former commercial site in a historically industrial part of West Seattle. The area is hot these days, with bland new townhouse construction selling for top dollar. Hybrid’s Steel Stacks offerings are competitive with developer-led construction, but with a much stronger value equation—chief among them better function, better aesthetics, and more street-friendly design.
The four Corten-clad units (a nod to the area’s industrial legacy) are flipped in plan. There’s a roof terrace, a top-floor kitchen/living/dining area, two bedrooms with a shared bath on the second level, and a flex space on the ground level. The flex space is what adds quantifiable value to the units. Each has its own entrance that can be locked off from the main dwelling, a small kitchen, a bathroom and shower, plus a dedicated patio space. The flex units give buyers the option to rent the space as a standalone apartment or to take on a roommate while maintaining an extra measure of privacy.
True to its name, the financial arrangements Hybrid uses to develop these properties are an inventive mix. The firm often partners with existing owners of commercial or single-family properties. Hybrid provides the design, construction, and development work in exchange for an ownership share at the permitting stage. With the Steel Stacks project, the owner subdivided the property and retained a small commercial space that will become a café and dog-washing business.
“The opportunity is working with owners who want a stake in developing their own land,” Robert explains. “I’m doing another project right now with one of my neighbors. At the end of the day, she’ll get a new unit worth $1 million with a mortgage of $100,000—and she gets to stay in the neighborhood she’s lived in for years.
“We are interested in community,” he continues. “We want to make housing more accessible without losing track of what makes it feel like home and what creates a sense of place. Architects talk about change, but we look at it passively. We are the catalysts of change and we’re not silent players. We are the most active player.”
Residential Special Constraints
Architect: Robert Humble, principal in charge, Hybrid Architecture, Seattle
Builder: Hybrid Assembly, Seattle
Developer/Owner: Hybrid Development, Seattle
Interior Designer: Hybrid Architecture
Landscape Architect: Glenn Takagi, Seattle
Project Size: 6,400 square feet
Site Size: .10 acre
Construction Cost: $225 per square foot
Photography: Rafael Soldi, Alex Herbig
Cladding: Western States Metal Roofing, standing seam Corten siding, fir tongue-and-groove painted wood siding
Door Hardware/Locksets: Emtek, Schlage
Faucets: Delta Trinsic
Flooring: Carbonized engineered bamboo
Lighting: Progress, WAC
Sinks: Elkay, VIGO
Vent Hood: Miseno
Windows: Lindsay Windows
Plans and Drawings