Click here for a FEMA publication that deals with selecting refuge areas in buildings. Here’s a description of the booklet pulled from the site:
This booklet presents case studies of three schools that were struck by tornadoes: Xenia Senior High School in Xenia, Ohio; St. Augustine Elementary School in Kalamazoo, Michigan; and Kelly Elementary School in Moore, Oklahoma, which were struck on April 3, 1974; May 13, 1980; and May 3, 1999, respectively. The resulting damage to these schools was examined by teams of structural engineers, building scientists, engineering and architectural faculties, building administrators, and representatives of the architectural firms that designed the buildings.
From these and other examinations, guidance has been developed for selecting the safest areas in existing buildings – areas that may offer protection if a tornado strikes – referred to in this booklet as the best available refuge areas. The guidance presented in this booklet is intended primarily to help building administrators, architects, and engineers select the best available refuge areas in existing schools. Building administrators, architects, and engineers are encouraged to apply this guidance so that the number of injuries and deaths will be minimized if a tornado strikes an occupied school.