This primer describes the current state of seismic isolation technology and highlights issues and concerns which are unique to the design of isolated structures. Readers will rapidly gain practical knowledge related to base isolation design from this concise book. Included are the fundamentals of seismic isolation, design of isolated structures, analysis, and testing. Provided are overviews of the topic that are accessible not only to structural engineers who have not been formally trained in base isolation design, but also to architects and students in a first-level engineering course. This book emphasizes practical issues, rather than theoretical issues, making it complementary to textbooks on earthquake engineering.