You learn a lot about things you didn’t know you didn’t know when designing a house. Like shear walls.
Soon after that shaking begins, the electrical grid will fail, likely everywhere west of the Cascades and possibly well beyond. If it happens at night, the ensuing catastrophe will unfold in darkness. In theory, those who are at home when it hits should be safest; it is easy and relatively inexpensive to seismically safeguard a private dwelling. – The Really Big One, The New Yorker
A shear wall is a strategically-placed wall designed to transmit lateral forces caused by, say, an earthquake, into the ground. The city of Seattle requires seismic code compliance for residential architecture. Our current house, built in 1900, has no shear walls, let alone the required added redundancy for earthquake protection; we are grandfathered in to a house of cards.
But, lulled into nonchalance by their seemingly benign environment, most people in the Pacific Northwest have not done so. That nonchalance will shatter instantly. So will everything made of glass. Anything indoors and unsecured will lurch across the floor or come crashing down: bookshelves, lamps, computers, cannisters of flour in the pantry. Refrigerators will walk out of kitchens, unplugging themselves and toppling over. Water heaters will fall and smash interior gas lines. Houses that are not bolted to their foundations will slide off—or, rather, they will stay put, obeying inertia, while the foundations, together with the rest of the Northwest, jolt westward. Unmoored on the undulating ground, the homes will begin to collapse.
Our new house, though, will be much safer. In addition to seismic building code compliance, we’re embracing post-modern design, with a focus on classic, symmetrical proportions, which are preferred for earthquake retrofitting. That and we’re embracing the constraints.
The architect should be prepared to accept structural forms or assemblies (such as increased size of columns and beams) that may modify the design character, and should be prepared to exploit these as part of the aesthetic language of the design rather than resisting them.
The architect and engineer should both employ ingenuity and imagination of their respective disciplines to reduce the effect of irregularities, or to achieve desired aesthetic qualities without compromising structural integrity. – Seismic Issues in Architectural Design, Fema.gov