A new townhouse development in Seattle has created a distinctly rural yet eco-modern village environment within an urban setting.
Bradley Khouri of B9 Architects designed the seven-townhome Urban Canyon project, sketching by hand using Graphisoft's ArchiCAD 3D building information modeling (BIM) software. His goal was to create an environment that maximized occupant density while incorporating sustainable technologies and open, free flowing "canyon" spaces where community members could share and interact.
Urban Canyon was one of the first recipients of the Built Green Incentive, a Seattle funding program that fosters green development in the city. Urban Canyon incorporates innovative green building technologies and techniques that incorporate a sense of community. These include a shared gardening area that Seattle locals call a "Pea-Patch," a solar-powered community bike shed, green roof decks, a 100% pervious site (outside of the buildings' footprints), and a greywater system that supplies water to all of the toilets.
In designing and constructing the buildings and landscape, B9 and the developer, gProjects, made conscious material choices. This included innovative use of concrete in multiple forms and locations at the interior and exterior of the project. The elements range from finished materials at the interior to structural retaining walls and exterior paving solutions.
Because of the change in grade across the site, the eastern most units are set a half story lower into the ground. Concrete retaining walls at this grade change are featured in certain interior spaces and insulated from the outside accordingly. In addition, the lowest floor of each home, in most cases this is the main living space containing kitchen, dining, and living areas, is an integrally colored concrete slab on grade. The slab provides radiant heat, with hot water running through it.
In each unit's suite, the bathroom floor, tub surround, shower curb, and shower floor are finished with concrete tiles containing recycled ceramic aggregate. At the exterior, private patios for each home and parking areas are made from reused concrete, taken from sidewalks that needed to be replaced surrounding the project site. The developer used a mix of large pieces, that a skilled excavator relocated, and small pieces placed by hand.
Small retaining walls built from the remaining reusable concrete add character onsite and keep material usually discarded onsite. The driveway into the site is made from grasscrete: precast concrete elements that are placed at grade and filled with soil that is then seeded for grass to grow in between. This makes the driveway pervious to runoff and green for visual and environmental benefit.
Because Urban Canyon was a speculative project, using an ArchiCAD BIM model was instrumental in helping B9 Architects balance the competing demands between custom, site-specific design and the financial constraints inherent in speculative construction, according to Khouri.
"The ability to do everything from massing to lighting studies within a single BIM model enabled us to test, change, and refine a variety of design ideas quickly and easily," he says. "I was able to share the model and collaborate with my client, the builder developer, gProjects LLC, evaluating the spatial and light quality and relationships between structures and their various roof lines. The ArchiCAD model is also a great presentation and marketing tool. We used it to create marketing drawings by simply turning on and off the various layers of the design documentation and used multiple renderings modes to create explain the design intent to the neighborhood Design Review Board."
The architecture makes heavy use of recycled materials, including the reclaimed brick and wood exterior that form the walls and ground of the pedestrian "canyon." All front doors are accessed off the canyon, directing owners and their guests through the winding volumes of the village. With widths ranging from 10 to nearly 18 feet wide, and from 15 to 25 feet in height, the volumes and light are changing continually, creating an intriguing experience. The massing includes vegetative roof decks with views back into the canyon and to the Cascade Mountains to the east for all homes.
Permanent artwork hangs on the walls of the canyon, and whimsical mailboxes further enliven the space. The canyon's orientation allows for southern light and air to reach all of the homes and penetrate the site.
To view pictures of the projects, visit B9 Architects.