FEMA P-320, Taking Shelter From the Storm: Building a Safe Room For Your Home or Small Business (2008)
Having a safe room built for your home or small business can help provide “near-absolute protection” for you and your family or employees from injury or death caused by the dangerous forces of extreme winds such as tornadoes and hurricanes. Taking Shelter From the Storm, Building a Safe Room For Your Home or Small Business, FEMA P-320, now in its third edition, helps home or small business owners assess their risk and determine the best type of safe room for their needs. The publication provides designs for basement, in-ground, and above-ground safe rooms.
The construction plans and specifications are available in DWG and PDF formats and can be downloaded from http://www.fema.gov/media-library/assets/documents/26215.