Having a safe place to retreat to during dangerous weather conditions can mean the difference between life and death. A storm shelter provides a durable, comfortable shell to protect inhabitants against extreme winds up to 250 miles per hour and any dangerous debris it can fling about, even if the home itself doesn’t make it. In this guide, we’ll go over what to know when building a storm shelter.
What is a Storm Shelter?
According to FEMA, storm shelters are defined as buildings, structures, or portions thereof that a building operator designates for use during tornadoes, hurricanes, and other severe windstorms.
These shelters are designed to preserve life in extreme weather conditions as intense as F5 tornadoes or C5 hurricanes. Winds from an F5 tornado reach speeds between 261 and 318 miles per hour, as defined by the Fujita Scale.
If one of these weather events occurs, residents can retreat to a storm shelter for the duration of the storm. The interior of a storm shelter can be as simple as just a few seats and ventilation or it can be equipped with food storage, running water, and sleeping areas.
Things To Know When Building a Storm Shelter
Whether the idea is to construct a bare minimum shelter or create a relatively comfortable space, there are some factors to consider when building a safe room for storms.
Local regulations and permits
The first thing to look into is your local regulations and permitting. Local building departments may or may not allow certain types of storm shelters. They will also require plans to be submitted and approved by the local building inspector.
Some part of this check-in is to ensure that the town is aware that your home has a storm shelter (emergency personnel need to know where to check after the storm). It’s also to ensure that the shelter is safe and built up to code. After all, a shabby storm shelter can become a hazard just as fast as the home itself.
Types of storm shelters
There are several types of storm shelters including above-ground, underground, residential, and community.
- Above-ground storm shelters are built on a concrete slab above grade. They’re easier to build but won’t provide as much protection from the elements as a below-grade underground shelter. However, in areas prone to flooding, they may be the only option (if they’re allowed at all).
- Underground storm shelters are built below grade, whether they’re installed in basements, crawl spaces, or bare earth excavated for their construction. These shelters are set up best for surviving extreme weather conditions. That said, they’re difficult to build and may not be allowed in flood-prone areas.
- Residential storm shelters are designed to hold up to 16 people, by FEMA’s definition.
- Community storm shelters are designed to shelter more than 16 people.
In the case of both residential and community shelters, there are certain FEMA standards to follow for square footage per person.
It’s also important to understand that a storm shelter should be attached to a concrete foundation, whether it’s a solid concrete pad or the home’s basement. However, it should not be attached to the building itself. If the home were to tear off the foundation, the shelter should be able to remain in place.
Construction materials
Storm shelters need to be built from durable materials that can withstand the potential impact of a storm while protecting the people inside. There are several types of materials that can be used:
- Concrete block with reinforced steel rebar
- Poured concrete with steel rebar
- Reinforced concrete with fiberglass
- Wood and steel
- Plywood and steel
There are also precast concrete storm shelters that homeowners can purchase from a manufacturer. These units are installed on-site and take all the guesswork out of constructing a safe shelter.
DIY or professional construction?
You’ll need to think long and deeply about this point. While you could DIY your own storm shelter, it’s important to gauge your own building skills, the complexity of the materials and the design you’ve chosen for the project, as well as the amount of time you’ll have to construct your shelter before dangerous seasons approach.
If budget allows, it’s often better to hire a professional to build your storm shelter. Pros work faster and have the tools and experience to work with a wide variety of materials. They can also design and create plans faster than DIYers typically can, moving through the permitting process faster.
Design considerations
There are some design elements to think about when building a storm shelter. For example, storm shelters require ventilation to prevent suffocation. They also need to be able to withstand changing pressures. Doors should be secure but also swing inward in case debris were to block the entranceway.
Other considerations include utilities like electricity and water. These utilities often go out during a storm, but a storage tank of fresh water plumbed to a sink and toilet can help keep things sanitary. Similarly, access to a portable solar panel system and power station can help charge devices when the storm ends. A hand-cranked emergency radio is also an important power-outage essential.
Creature comforts are also worth investing in. Some shelters have drop-down bunks for sleeping. Storage for food and drinking water will help inhabitants wait out longer storms.
Secondary uses
Storm shelters can even serve alternate purposes as well. This space can be designed to be used for food storage, a wine cellar, an outdoor storage area, or even hangout spot, depending on the size. Some might even consider turning their storm shelter into a home gym—as long as the equipment inside were easy enough to move quickly during the onset of a storm. Keep these secondary uses in mind when developing your plans for your storm shelter.
How Much Does It Cost to Build a Storm Shelter?
It depends on the design, chosen materials, and the extras involved, but a storm shelter can cost as little as $3,000 for an above-ground safe room or as much as $30,000 for an in-ground shelter. Adding lights, beds, and other extras will drive up the price. In most cases, using a contractor to build the shelter will cost more than DIYing.
FEMA Guidance
The Federal Emergency Management Agency published a guide on safe rooms and storm shelters in 2021. This guide provides all the information one might need to design a safe room that meets FEMA standards, including economic considerations, maintenance requirements, structural design criteria, occupant density, and testing methods for impact and pressure testing. Keep in mind this document is over 200 pages long, but it’s available for free online.
Safety is Always the Number-One Priority
Regardless of how well you design your storm shelter, it is always wise to evacuate immediately as long as you can do so safely. A storm shelter in a storm is never safer than a haven far removed from the storm’s path. This is probably the most important consideration of all.
