Regardless of the price, storm shelters that meet the Federal Emergency Management Agency design criteria for wind-born debris provide near-absolute protection when built or installed according to regulations. FEMA design criteria require that a storm shelter withstand a 15-pound two-by-four being hurled at the shelter wall at 100 mph.
Storm shelters fall into two different categories: community and residential. Storm shelter building standards far exceed the regular building code for a geographic location. A storm shelter or safe room may be a reinforced interior room, an underground room or a separate building. FEMA publishes guidance on designing and building safe rooms at FEMA.gov under the Plan, Mitigate and Prepare tab.