Pros and Cons of an Underground Bunker

Prepping has become a favorite pastime for a lot of people. This may be partly due to the ease in finding out about the disasters that strike every day in some part of the world. There are apps that show earthquakes in real time, apps that keep up with volcano activity, and news apps from anywhere in the world. Becoming more aware of catastrophes may encourage people to prepare themselves and their families in case the disasters strike closer to home.

One of the things that come to the mind of many survivalists is a bunker. This is a sturdy location to wait out a storm, nuclear fallout, or some other dangerous situation. The idea comes from the military, which uses them for protection from artillery and has built some of the biggest bunkers in history.

This type of safe house can be built above ground or underground, but it seems people assume that underground is safer, for a variety of reasons. One of these is that the layer of earth adds an extra layer of protection, and it also makes it somewhat less noticeable in some cases.

Underground bunkers can be made from different materials. These include steel, concrete, and pipes or culverts. Each of these has its own positives and negatives.


  • Higher chance of survival.
    Because a secure location with solid walls is protection against flying objects, nuclear fallout, and potentially marauders, it increases the chance of survival if it is properly installed and sealed.
  • An easily accessible place of safety.
    Rather than having to go across town to get to a safe place, having a bunker under the back yard is convenient and easy to get to.
  • Protection from storms.
    The solid walls and layer of earth will keep winds, rain, and flying debris from being as devastating to the people of the household, regardless what happens to the other structures on the property.
  • Protection from fire.
    Dirt and steel, concrete, or pipes are flame resistant (generally even fireproof), which means it can be a safe place to wait out a wildfire, if set up properly.
  • Privacy.
    Unlike a public shelter, where one is joined by strangers, a personal bunker will usually house only the family that owns it. Anyone else joining the family is likely to be a close friend or neighbor who has been invited to do so.
  • Storage.
    The bunker is an excellent place to store supplies that would be needed in the case of a catastrophe, regardless whether or not the shelter itself becomes required. Food, water, first aid, and other supplies can be stored indefinitely inside the bunker. Remember to check stock regularly to use the oldest and replace with new, so the oldest items will not become too old to be usable.
  • Stress relief.
    Knowing that the shelter and the supplies that have been placed inside are available if they are needed can remove a lot of stress from the household. Even if something dangerous seems imminent, being prepared can ease one’s mind.
  • Cylinder shape.
    Choosing an underground bunker that has a rounded shape is safer than a squared shape. With a rounded shape, the surrounding dirt will be better supported. This will allow more surrounding dirt to protect the shelter without crushing it.
  • Insulation.
    The extra dirt around the shelter will help keep the interior a steadier temperature; easier to heat and cool as needed due to the insulative properties of the earth.


  • Single entrance/exit.
    Unless the shelter is built with a back door, the hugest weakness of an underground shelter is the lack of an extra exit. If the entrance becomes blocked, the lack of another way out can be much more dangerous than whatever one is sheltering to escape.
  • Ventilation.
    Because oxygen is required, a sealed underground shelter must have some sort of ventilation. This is necessary, but not always easy to accomplish.
  • Water.
    Storing water for emergencies is great, but if the shelter is needed for an extended time, having no way to get more water will be a detriment.
  • Light.
    There is no natural light underground. Unless there is some way to get light from outside, the lack of light can make day and night get confused and cause other problems such as seasonal affective disorder or depression if an extended stay is required. Leaving the shelter regularly can help with this, if it is possible.
  • Flooding potential.
    Because it is underground, the potential of flooding is somewhat higher, especially if it dips below sea level or the level of the local water table. There have been several cases of people sheltering underground and the shelter flooding with them trapped inside, resulting in their demise.
  • Vulnerable entryway.
    In the case of danger from human attackers, such as in a war or riot situation, the entry of a shelter can be very difficult to shore up in a way that it cannot be breached.
  • Less defensible.
    Having the low ground gives shelter inhabitants an inferior position in the case of battle. It is always more difficult to defend against someone above.
  • Mold.
    Mold loves dark, moist locations. These conditions are quite common in the underground, and it would be difficult to ensure that the inside of a bunker was warm and dry enough to resist mold and mildew.
  • Cave-in.
    If the shelter is not properly supported, it could collapse. This is not a common situation, but it can happen.
  • Fire risk.
    In some shelters, the interior is framed out with wood and drywall. This and some of the common supplies are flammable, so there is a chance they could catch fire.
  • Staying warm.
    However, underground tends to be cooler, so heating the shelter is likely to be needed if it is used in the wintertime, especially. Lighting a fire is unwise, both because of the fire risk and because fire consumes oxygen, which is already limited, even with proper ventilation.
  • Waste disposal.
    Like the title of the popular children’s book, “Everybody Poops.” This is not something that must be considered very often normally, since every house has a bathroom with a flushing toilet, but in the case of an underground bunker, something has to be done with it, and few bunkers are outfitted with flushing toilets.
  • Mental health.
    With the lack of daylight and potential claustrophobia, some people may not be able to handle being underground for long, if at all.
  • Cube shape.
    Some have suggested burying shipping containers for underground bunkers. This is not a wise plan. Shipping containers are built to be stacked on top of each other and are not meant to have pressure on the sides. Burying one of these will put the pressure of the earth around the container on all sides, which could result in the sides of the container buckling.
  • Expansion.
    Getting a bunker underground requires digging. Because of this, it can be difficult to expand at all, if it is possible at all. Therefore, whatever size is installed is probably all that will ever be there.
  • Potential of debris damage en route.
    Having to go outside to get to the bunker means going into the dangerous environment from which the household is planning to safeguard. Environmental dangers can cause injury in the time required to get from the house to the bunker and inside.