Standards & Codes
FEMA P-320
Also known as: P-320, Taking Shelter From the Storm, FEMA residential safe room guide
What P-320 covers
P-320 is written for homeowners, builders, and design professionals. It treats the safe room as a complete assembly: walls, roof, door, anchorage, and ventilation must all be tested or detailed together. A wall that passes impact testing does not make a P-320 safe room on its own.
Design event in P-320
- Design wind speed: 250 mph, 3-second gust
- Wood 2x4 missile: 15 lb at 100 mph horizontal, 67 mph vertical
- Continuous load path from the shelter shell to the foundation
- Ventilation that maintains breathable air for the design occupancy without breaching the envelope
P-320 vs P-361
P-320 is the residential document. P-361 is the criteria document for community safe rooms (schools, public buildings). Both reference ICC 500. If you are buying for a single-family home, P-320 is the applicable reference.
Distinguished from
- ICC 500
- ICC 500 is the underlying consensus standard with test procedures. P-320 is a federal guideline that points to ICC 500 and adds detailing for residential applications.
- FEMA P-361
- P-361 covers community shelters; P-320 covers one- and two-family residential safe rooms.
Practical example
A buyer asks the installer for the P-320 reference on the plans. The installer points to a sheet that cites P-320 figure numbers for wall section, anchor detail, and door schedule, and attaches the door manufacturer's ICC 500 test report. That documentation set is what a state rebate reviewer expects to see.
Authority: FEMA P-320, 5th edition. Last reviewed 2026-06-04.
Looking for prices instead of definitions? See current price ranges or get matched with installers.