The Tsunami-Resistant Crestwave House

Capri Architecture and Cunningham Built designed and constructed a home engineered to withstand the harsh conditions at the Oregon Coast.

The awesome power and beauty of the Oregon Coast has been on the mind of Curt and Deb Rose since 1998, when they first purchased their 1930s-era Yachats cottage. Curt often battled rain and gale-force winds while trying to pin down flapping roof sections. The whole house shook when the surf pounded the cliffs below.

So when they decided to construct a new home on the same site, the elements loomed large. But it was the so-called “big one”—a Cascadia subduction zone earthquake with the potential to level any home built in the tsunami zone—that guided the design.

“We wanted the property to last for generations—not just our life span, but for our kids and their kids and so on,”says Curt. “The probability of a major tsunami event in our lifetime is relatively modest, but in generations to come, it’s a near certainty.”

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Engineering for the Unknown

Architects Dustin and Amanda Capri took on the challenge of designing a 2,800-square-foot, three-bedroom, three-and-a-half bath, earthquake- and tsunami-resilient home that complied with zoning requirements and leveraged the beautiful Pacific Ocean views.

The design process was a collaboration between the homeowners, Capri Architecture, Cascade Design Group (the lead structural engineer), a certified engineering geologist, and general contractor Blain Cunningham, owner of Cunningham Built.

Consulting maps from Oregon’s Department of Geology and Mineral Industries (DOGAMI), the team determined that the home, sited at 43 feet, should be elevated to over 50 feet. This approach elevates the home above DOGAMI’s “small,” “medium” and “large” Cascadia subduction zone tsunami events.

To help the home withstand a 9.0 earthquake event, the team employed 16 micropiles beneath the foundation that essentially lock the home in place. The micropiles extend downward 35 feet into solid bearing material and are angled to resist lateral-spread forces. The micropiles are then pinned to a grade-beam style foundation supporting a ground-level concrete core and a series of concrete piers with walls designed to break away in a tsunami, leaving the top two floors of the house intact.

While Dustin Capri is quick to point out that the home isn’t designed for unknown factors like tsunami debris, they made as many decisions as they could to improve the survivability of the structure.

“We created a responsibly developed home within the tsunami inundation zone, within the client’s budget, and meeting their goals aesthetically and from a tsunami-preparedness standpoint,” says Capri.

The additional engineering is similar to what might be found in a commercial project rather than a single-family home, and accounted for an extra 10% to 20% of the total building costs.

“There is clearly an extra cost, but with the cost of building today, it might be justifiable if you anticipate owning for 50 to 100 years or passing your home through the family,” says general contractor Cunningham. “It’s possible with a few extra steps in the planning process.”

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Designing for Family, Now and Into the Future

Tsunami or no tsunami, the homeowners wanted Crestwave House to be a flexible and low-maintenance home that supported multigenerational living, highlighted the views and where they could age in place.

Three independent living areas comfortably accommodate the couple’s grown children and their families. There is an elevator and a lot of smarthome automation. Everything of value is positioned on the second floor and above.

Full-height windows frame expansive views from Yachats to the heights of Cape Perpetua. In reflective surfaces like black glass behind the cooktop, the ocean views go on and on.

“You can sit at the dining room table with your back to the windows and still see the sunset,” says Deb Rose.

On the lower breakaway level, garage doors open to create an indoor/outdoor space equipped with heaters, a ping-pong table, a bar and an adjacent fire pit. On a beautiful day, it offers incredible views and wind protection.

“We go to sleep at night and don’t worry if the big one is going to hit,” says Deb. “It is very comforting knowing that generations of our family will be safer in this house.”