2023 180 E1

Seismic Performance of Tiny Homes

By: Steffi Win

Department: Engineering

Faculty Advisor: Dr. Jenna Wong

California has the highest percentage of homelessness accounting for 30% of the national total. To tackle the growing homelessness issue, some cities have been utilizing tiny homes, which are typically under 225 square feet (SF), as a solution for transitional housing. The lack of regulations on tiny homes has become a concern for high seismic regions such as the San Francisco Bay Area where these homes are being implemented. In recent studies done at San Francisco State University, a comparison between a representative shed and tiny home designed per the International Residential Code (IRC) show higher base shears than expected. This suggests the possibility of sliding as these homes are not required to be anchored to the foundation. To further examine these structures’ performance for seismic motions, shake table tests on full-sized tiny homes (timber structure and commercial shed) were conducted for anchored and unanchored scenarios. These shake table tests were conducted at the UC Berkeley Pacific Earthquake Engineering Research Center. A full instrumentation plan was developed on both structures to record displacements and accelerations. The experimental tests presented a wealth of quantified data to compare the structural performance of these systems. The initial observations confirmed analyses’ predictions of full home movement via sliding, areas of unexpected damage especially for the shed structure, and gave insight into anchoring systems. This project opens the discussion for better regulation and oversight for tiny homes as their presence increases with recent California legislation expanding use of auxiliary dwelling units to address the widespread housing crisis.