In some municipalities, a permit is required, with FEMA publishing guidelines for building a safe room (FEMA P-361 and P-320). Permit costs can range from $430 to $2,240.
FEMA funding may cover up to 75% of the cost of a storm shelter. The federal government distributes money to states, which set their own requirements. To find out your options, contact your State Hazard Mitigation Officer.
Storm shelters can add up to 50% of the unit cost in resale value. This applies most in areas where hurricanes or tornadoes are common. Some homeowners have increased the value of their underground safe rooms by using some of the space for a gun safe or wine cellar.
With no building expenses, a pre-built shelter typically costs less to buy and install. They're also available in various sizes and materials, making it easy to choose the one that's right for your family's needs.
Most pre-built storm shelters take four to eight hours to install. Custom-made options or installations requiring land excavation can take days or weeks to build the structure from the ground up.
FEMA recommends at least six square feet per person during a tornado and 10 square feet per person for a hurricane. For example, a 5-by-6-foot shelter is suitable for a family of five in a tornado-prone area.