Seattle Firm Designs DADUs as an Affordable Housing Option
/Johnston Architects has designed a number of detached accessory dwelling units (DADUs) for both rural and urban applications. You can read the article by Symone Strong in its entirety at Builder Magazine.
In Twisp, Washington, the founding partners of Johnston Architects added a new DADU prototype called Casita behind their existing Twisp Cabin.
Accessory dwelling units or ADUs have been trending terms in the housing industry for the past few years, as many U.S. cities have recently altered zoning laws to accommodate secondary units on single-family residential lots. The housing type, which can be attached to or detached from a main residence, not only provides additional space for a homeowner or their guests, but also increases density and offers a solution to increasing the affordable housing stock.
In an effort to create unique and accessible ADU plans in the Pacific Northwest and beyond, Seattle-based Johnston Architects has designed a number of ready-to-build, detached accessory dwelling units (DADUs). Plans for four designs, including the firm’s initial Twisp Cabin and new Casita, Origami, and Gable DADUs, are available for purchase. The firm also has developed software to allow future clients to customize the Casita plan to fit their specific needs and lot requirements.
“The basic premise for the Twisp Cabin was to create a simple dwelling with high-quality materials. There’s a good deal of cedar, concrete, and steel. It’s a simple palette that endures for a long time and weathers very well on-site.”
In 2013, the firm replicated the plan for the first time on Orcas Island in the San Juan Islands of the Washington coast. Besides the sloped and rocky site, the overall Twisp concept, including the floor plan and materials, were relatively unchanged. Today, the firm is working on a cross-laminated timber version in Oregon and is offering the architectural plans to anyone interested across the U.S. for $7,000, according to the firm’s website.
During the peak of the pandemic, the Johnstons retreated to the original Twisp Cabin and ultimately decided to expand the living space on the 11-acre lot by developing the Casita DADU prototype behind the original cabin built 16 years ago.
Completed in March of this year, the Casita model encompasses roughly 790 square feet, broken down into 450 square feet of interior space, a 64-square-foot sauna, and 240 square feet of covered patio and outdoor shower space.
the casita is the twisp cabin’s adorable little sister
Looking ahead, the firm hopes both the Twisp Cabin and Casita plans will help homeowners fulfill their DADU goals, but the partners are also open to new designs as well.
“It’s one of those things that we’ve put out in the office to our architects,” says Chaffin. “If they come up with a product, house, or DADU that they think is really cool and fits a niche that we’re not addressing right now, we definitely would add that into the mix.”
the twisp cabin - photos by benjamin drummond
“The Casita was an evolution of what we were doing with the Twisp Cabin. We came up with the Casita as sort of this very simple, yet we hope elegant, way of creating multiple different types of DADUs to accommodate a person’s or family’s needs.”
the casita interior mirrors a studio guest cottage with a bedroom, a wood stove, a kitchenette, storage, and a full bath