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Adding a Storm Shelter – The Best Option

The best option for safety during a tornado is an ICC 500 or FEMA P-361 storm shelter. Both have similar requirements.

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With students and staff spending a large portion of their day in the school building, having a designated safe area for use during a tornado is critical. The best option for student and staff safety during an extreme wind event is an ICC 500 Storm Shelter or FEMA P-361 Safe Room. Both have similar requirements, although a Safe Room is required if federal funding is provided by FEMA. These facilities are specifically designed to withstand tornado wind forces per code prescribed requirements including:

  • All of the openings in the walls and roof are designed to resist impact forces from flying debris.
  • The walls and roof construction are designed to withstand high wind forces and debris impact.  The interior of the shelter must include restrooms and other features.
  • Typically, the shelter will have its own mechanical system and generator.

When to Add a Storm Shelter: As Part of Your School’s Addition Project
If you are planning an addition to your current facilities, or planning to add a new school, that’s a great time to add a storm shelter. According to data from FEMA, the cost to add a storm shelter or safe room is approximately 20% to 30% greater than the cost of standard construction. This increase in cost only applies to the shelter space itself and not the entire addition.

A tornado safe structure was added to an existing high school. The addition houses two multi-use rooms (wrestling and weight rooms), restrooms, storage room and vestibule.

Shive-Hattery has designed ICC 500 shelters as part of school additions in the past few years. In most cases, some of the daily use spaces already planned for the project were designed to also meet storm shelter requirements.  The spaces were already part of the addition, but the design was changed at the beginning of the project to provide a shelter during a tornado as well as space for daily use. The size of the shelter depends on the school population and finding a space with fewer openings to protect. Many schools prefer to use the gym for this space because it can house the entire school population in one location. However, smaller areas may be more cost effective and capable of providing the space required. FEMA ICC-500 recommends 5 square-feet of space for each individual in the shelter with some adjustments for ADA accessibility.

Minimizing the number and size of openings will reduce the cost of debris protection, but that doesn’t mean you cannot have openings in a shelter. Window protection comes in many forms such as shutters or debris resistant glazing. ICC 500 missile test-rated double or single doors are available as ICC-500 missile test rated. Mechanical unit air intake and exhaust can be protected with ICC-500-rated louvers.

We are seeing many jurisdictions adopt code provisions that require the construction of a Storm Shelter during new school construction or addition projects.

Regardless of frequency, it is important to be prepared and ready to respond to natural hazards. Our Extreme Wind Event biweekly-series is intended to help walk you through identifying vulnerabilities and opportunities to improve safety for your schools. Topics included: