- Structural Engineer:Harriott, Valentine Engineers (Jim Harriott, P.E. , Elizabeth Lozner) Surveyor:Jouni Paavola
- Passive House Consultant:Brett Holverstott
- Clt Consultants:atelierjones LLC (Susan Jones, Joe Swain, Brian Gerich), WoodWorks (Ethan Martin), ARUP (Hans-Erik Blomgren, P.E.)
- Contractor:Cascade Built LLC (Sloan Ritchie, Terry Ducatt, Mark Hughes, Al Fernandez, Nicole Pi, Kirk Hochstatter
- Clt Fabrication/Cnc:Structurlam (Ron McDougal, Thor de Vos)
- Wood Fabrication Services:Euroclime LLC (Kim Nguyen)
- Subcontractors:Charles Stratton Cabinets, Solar Innovations, Sky Hatch, Rubelcon, Siding, Small Planet Workshop, PH Envelope materials, Truescapes, Landscaping, Leader/Fairweather, Site Furnishings, West Coast Wire and OSP Sling, Yacht Harness, Katwall Inc
Text description provided by the architects. CLTHouse is a modest single family house for a family of four in urban Seattle. Situated on a small, leftover 2,500 sf triangular lot, the house negotiates between an oversized alley and rear bank parking lot, and an established neighborhood near Lake Washington. The materiality of the house recalls ubiquitous small Pacific Northwest beach cabins, as well as specifics of the site: once a beach itself, under 9’ of water in 1916. The house explores the dialogue between a blackened wood exterior, opening up to a whitened cross-laminated-timber (CLT) interior left raw, lightly whitewashed. Washed in light, textures and smells of natural materials, and to be surrounded in green, the house requires a tiny, vertical central service core. Channeling utilities from basement to roof deck, the core is shrouded with glossy white and ice-blue finishes, of unnatural materials – gwb, plastic-laminate, stainless steel and quartz. Surrounding the core, dramatic vertically lit spaces of the interior open up across through the kitchen core, through the staircase, up to the cedar roof deck with distant views of the lake. Spatially dynamic, reflecting the triangular site, the views are carefully screened and then revealed. Tectonically experimenting, the 67 CLT panels were pre-fabricated and routed using CNC technology, delivered to the site for erection in 12 days. Maximizing the power of CNC technology, some interior panels evoke pine knots, others are vaulted to create visceral experiences of light and space. Clad in burnt, shou-sugi-ban treated Douglas Fir, the house is blackened on the exterior, while the interior reveals the white, immersive, visceral natural experience.
Emerging from central Europe in the 90’s, CLT - from FSC-harvested regional timber - is emerging as a highly efficient carbon sequestration strategy, encompassing interdisciplinary efforts between wood fabricators and foresters, academics and practicing architects, policy makers and non-profit leaders. An alternative to more carbon intensive materials of concrete and steel, its use promotes mass timber as a viable and beautiful building material that if responsibly harvested becomes a highly sustainable strategy. The house required approximately 20 trees for construction, including 17 small-diameter Western White Pine trees required for the CLT-panel construction. In addition to harvesting these trees through FSC-certified sources, the owner’s family planted an additional 20 trees to act as carbon sequestration for decades to come. The first CLT structure to be permitted in the City of Seattle, and one of the first in the US to utilize CLT both as structure and finish material, the house has been a research vehicle for the firm over the last four years, and has been widely shared with a broad-based, interdisciplinary CLT community throughout Washington State from code and policymakers to academicians, and statewide AEC community. Construction completed in June 2015.