Questions to ask a storm shelter installer before you sign
A shelter is only as good as its design, its door and the way it is tied to the ground. These questions help you compare installers around Oklahoma City, Edmond, Moore and Norman on the things that matter. Checked November 2, 2026.
1. Can you show the design meets FEMA P-361 and ICC 500?
FEMA P-320 is the homeowner guide, FEMA P-361 holds the design criteria, and ICC 500 is the building-code standard for storm shelters. Shelter door assemblies must be listed and labeled to show ICC 500 compliance (FEMA P-320 (2025)). Ask which edition the unit meets. FEMA-funded prefab safe rooms must now meet FEMA P-361 (2021) and ICC 500-2020 (FEMA Safe Rooms page).
2. Is anyone claiming "FEMA approved"?
FEMA does not approve or certify contractors or products, and companies may not claim to be "FEMA approved" or "FEMA certified" (FEMA Safe Rooms page). If a sales pitch leans on that phrase, ask for the actual test reports and sealed drawings instead.
3. Are you an NSSA producer member, and will my shelter get a seal?
The National Storm Shelter Association is a non-profit whose producer members have their designs, plans and impact test results reviewed by a third-party registered engineer. Approved producers attach an NSSA seal to each finished shelter and file a Certificate of Installation, and NSSA keeps the shelter's location and seal number on record (NSSA homeowner information). Membership is voluntary, so a non-member is not automatically bad, but you can check a company on the NSSA residential shelter provider list. NSSA itself notes that no agency currently certifies shelters (NSSA industry standards).
4. Who pulls the permit and calls for inspection?
Oklahoma City requires a building permit for any above- or below-ground shelter: $99.50 for in-ground or slope-top, $104.50 for an above-ground safe room (City of OKC Storm Shelter Permit page). Moore's application lists a $34.50 fee and asks for a stamped engineer design (City of Moore shelter permit application). Del City requires installers to be licensed with the city and carry a $5,000 bond (Del City application). Get in writing that the permit is in the price.
5. How will it be anchored, and is my slab good enough?
FEMA publishes separate foundation and anchoring criteria and says the manufacturer's minimum foundation and anchoring requirements should go to you and the installer and be submitted with the permit (FEMA foundation and anchoring criteria). Ask whether your existing garage slab qualifies or needs new concrete. For in-ground and slope-top units in OKC, ask for the engineer's flotation letter (OKC Development Center).
6. Door, drainage and service
After the 2013 Moore tornado, Texas Tech found no major failures in 20 garage floor shelters but noted flooding, weak locks and worn rollers in some (Texas Tech Moore 2013 report). Ask about the door's locks, the drainage plan, who services the rollers later, and the written warranty. Then compare prices on our cost page.
Related: shelter costs · rebate status 2026 · in-ground vs garage · metro registries · installer questions