Storm Shelter Spec Reference
FEMA P-320 published guidance for residential storm shelters (by name only).
Reference
Topics
- Wind design FEMA P-320 wind speed for residential safe rooms; design event is the worst-case tornado / hurricane wind speed for the region.
- Occupant area FEMA P-320 published per-occupant area benchmarks for sitting and standing capacity.
- Anchorage Tie-down to foundation must resist uplift, sliding, and overturning per the published wind load calculation.
- Door and locks Door system must be tested to the FEMA P-320 missile-impact protocol.
- Ventilation Provide passive ventilation that resists pressure changes during a tornado or hurricane event.
FEMA P-320 by name only. No reproduction of figures or text.
Checked against published worked examples from: FEMA P-320 (cited by name only, figures and text not reproduced).
Details, formula, and sources
Formula or table(reference page; no compute) FEMA P-320 (Taking Shelter from the Storm) and ICC 500 (Standard for the Design and Construction of Storm Shelters) wind-design, anchorage, door, and ventilation considerations.
Source and editionFEMA P-320 (5th edition, 2021) by name; ICC 500-2020 by name.
Free accessFEMA P-320 free at fema.gov. ICC 500 read-only at codes.iccsafe.org.
What governsEstimate. AHJ and licensed structural engineer govern.
API field namescitation