How to Build an Underground Bunker [2023 Prepper’s Guide]

When it comes to preparing for a disaster or an uncertain future, building an underground bunker is one of the best ways to provide a safe haven for you and your family.

An underground bunker is a fortified structure that is designed to protect against natural disasters such as earthquakes, floods, and even nuclear fallout.

It is typically constructed deep underground, but can also be built above ground if necessary. The main benefit of an underground bunker is that it offers a secure and safe place for you and your family to hide in a crisis situation.

It can also be used as a storage area for food and supplies, as well as a secure place to keep important documents. If you are serious about building an underground bunker, there are some important considerations that need to be taken into account.

This article will outline how to build an underground bunker, and provide useful tips on how to make the process as smooth and stressfree as possible.

The first step in building an underground bunker is to determine what your specific needs are.

Consider what kind of environment you need to create, and how many people you need to accommodate. Do you need to store food and supplies, or do you just need a secure place to hide?

Also, consider what type of structure you want to build – do you want to build a concrete bunker, or a metal one? Once you have a clear idea of what you need, you can begin the process of designing and planning your bunker.

You’ll also need to consider a few core areas of your bunker, like size, layout, ventilation, protection, lighting, and other factors.

Size: What size bunker do you need to accommodate the number of people you plan to shelter?

Layout: What type of layout will provide the most efficient use of space with the least amount of excavation?

Ventilation: How will you ensure that the air inside the bunker is fresh and breathable?

Protection: What type of protection do you need from radiation and fallout?

Lighting: What type of lighting will you need for both safety and comfort?

Recommendations for Your Bunker

In this section of the article, we’ll give you recommendations to help you with those questions above. 


For those constructing a bunker as a refuge from a natural disaster, such as a tornado or hurricane, the size of the bunker should be sufficient to accommodate those who will be using it.

Depending on the size of the family or group of people, the bunker should be able to provide enough space to allow everyone to move around, store supplies, and remain comfortable.

The size necessary to provide sufficient space and provide safety from potential dangers, such as flying debris or falling objects, will also depend on the size of the family or group seeking refuge.

For those looking to use their bunker as a fortified base, the size of the bunker will be determined by the amount of space and resources available.

A bunker of this type should be large enough to contain supplies and equipment, provide fortified protection, and provide sufficient sleeping quarters.

For example, if you are looking to house multiple people and their supplies, you will want to build a large enough bunker to accommodate the necessary items and people.

This size also needs to consider the amount of space necessary to move around and address any potential medical emergencies that may arise.

Those looking to use their bunker as a hideout or a secure location will also need to determine the size of the bunker necessary.

This size should be enough to allow the user to move around without being seen and provide space for any supplies or equipment necessary for the mission.

When it comes to the actual size of the bunker, a good rule of thumb is to plan for at least 1,000 square feet of space. This will provide enough room to store food and water supplies, as well as accommodate everyone in the event of an emergency.


There are many different layouts, but my favorite is the step bunker layout. A stepped bunker layout is the most efficient way to use space with the least amount of excavation in a bunker.

A stepped bunker is designed by cutting a series of steps into a bunker wall, creating multiple levels that serve as shelves or platforms.

The steps act as natural walls and are used to secure and store items with minimal excavation. This layout optimizes the use of space in the bunker, letting you maximize the storage capacity without having to dig deep into the ground.

To begin, the bunker walls must be properly constructed.

Depending on the size and type of bunker you are constructing, you’ll need to ensure that the walls are at least four feet thick, reinforced with steel or concrete, and covered with an insulating layer to further protect the contents.

Once the walls are in place, it’s time to begin the excavation. Depending on the size of the bunker, and the number of levels you want to create, the depth of the excavation can vary. 

Generally, the initial excavation should be around twenty feet deep, although this can be changed depending on the size of the bunker and the number of levels you want to incorporate. 

Once the excavation is complete, it’s time to build the steps. To create a stepped bunker, you’ll need to build a series of steps into the side walls of the bunker. 

These steps should be around two feet in height each and should be constructed from steel or concrete reinforced with an insulated layer. This will help protect the items stored in the bunker and prevent them from shifting during an attack. 

Finally, you’ll have to secure the steps into the bunker walls. This can be done using bolts, screws, or rivets, depending on the type of bolts you have available. Once the steps are secure, it’s time to fill in the remaining space. 

Fill the remaining space with dirt, gravel, or sand. This will help to stabilize the structure and provide additional support for the contents stored in the bunker. Make sure that the ground is level and that it is properly secured, as this will help to keep the items stored inside safe.

Once the bunker is complete, you can begin to store items inside. By utilizing a stepped bunker layout, you can maximize the storage capacity of the bunker while using minimal excavation. 

This is a great way to keep your bunker organized and secure while using minimal space and resources.


The first step to ensuring the air inside a bunker is safe is to utilize an effective ventilation system. This system should be designed to allow for the exchange of air between the inside and the outside of the bunker.

This exchange of air will help reduce the risk of stagnant air and mold growth by introducing fresh, outside air into the bunker and allowing stale and contaminated air to escape.

It is recommended that a combination of natural and mechanical ventilation systems be used to ensure the air is filtered and properly circulated.

The next step to ensuring the air inside a bunker is breathable is to regularly maintain and clean the air. This can include using air filters to remove dust, pollen, and other particles from the air, as well as cleaning and replacing any filters as needed.

It is also recommended that a dehumidifier be used to help reduce the amount of moisture in the air and prevent the growth of mold and mildew.

Additionally, the use of an air purifier, especially in areas with high levels of pollution, can help to further clean the air and reduce the risk of respiratory illnesses and other health issues.

Finally, it is important to ensure the air inside a bunker is regularly tested. This can be done by using an air quality monitor to detect the levels of various pollutants in the air.

Testing can help to determine if the air is safe to breathe and if there are any areas in the bunker that need to be addressed. If any issues are detected, the necessary steps should be taken to address them and ensure the air is clean and breathable.


destroyed world

The first step to creating a safe refuge from nuclear radiation and fallout is designing a bunker that will provide the necessary protection.

A bunker must be constructed with materials that are capable of blocking radiation, such as lead, polyethylene, and concrete.

To ensure the bunker is capable of blocking radiation, it should be at least four feet thick and constructed in such a way that any radiation that is able to penetrate the walls will be reflected away from the inhabitants.

The second step to constructing a safe bunker is to make sure it is capable of resisting the shockwave from a nuclear blast.

The best way to do this is to build the bunker underground, as the earth will provide the necessary insulation from the shockwave.

In addition, the bunker should be reinforced with heavy steel beams and columns to further increase its resistance to the blast.

The third step is to ensure that the bunker is equipped with the necessary supplies to keep the occupants safe for an extended period of time.

This includes food, water, medical supplies, communications equipment, and other items necessary for survival.

In addition, the bunker should be equipped with a filtration system that is capable of filtering out any nuclear radiation, chemical agents, and fallout.

The fourth step is to have a plan in place to evacuate the area in the event of a nuclear disaster. This plan should include evacuation routes, safety zones, and shelters where individuals can seek refuge until the danger has passed.

In addition, it should provide information on where individuals can find medical assistance and other necessary supplies.

Finally, it is essential to have a plan in place to monitor and detect radiation levels in the bunker.

This can be done by installing radiation detectors, which can detect the presence of nuclear radiation within the bunker and alert the inhabitants to the danger.

By following these steps, a bunker can be designed and constructed to provide protection from radiation and fallout.

While no bunker can completely protect individuals from all the dangers of nuclear radiation and fallout, a welldesigned and constructed bunker can offer a safe refuge for individuals during a nuclear disaster.

With the right precautions and planning, a bunker can provide a secure environment in which people can take refuge from the most threatening consequences of nuclear war.


Lighting is an essential component of creating a safe and comfortable environment in a bunker. Proper illumination not only allows you to better move around and identify potential hazards, but it can also make the space feel more inviting and prevent mental fatigue.

The first type of lighting to consider when designing a bunker is task lighting. Task lighting is used to specifically illuminate areas where certain activities take place. 

This type of lighting is useful for performing tasks such as cooking, cleaning, or reading, and it can be used to effectively light small areas without the need for additional fixtures. 

Task lighting can provide focused illumination and eliminate blind spots, ensuring that activities can be performed safely and accurately. 

The next type of lighting you should consider is ambient lighting. Ambient lighting is used to create a general brightness in a room, and it is typically used for aesthetics. 

Ambient lighting is useful for making a bunker feel more inviting and can be used to add atmosphere and interest to a space. It can also be used to draw attention to specific areas, such as artwork or other decorative elements. 

The final type of lighting to consider is accent lighting. Accent lighting is used to draw attention to specific features in a room and can be used to create a dramatic effect.

Accent lighting can be used to highlight artwork, structural elements, or even plants and other objects. It can also be used to create amood in a space and provide a sense of comfort and security. 

When it comes to selecting the right type of lighting for a bunker, it is important to consider how the space will be used. If there are activities that require focused illumination, such as reading or cooking, task lighting should be used. 

For general illumination, ambient lighting is the best choice, while accent lighting can be used to add atmosphere and highlight specific features. 

In addition, all lighting used in a bunker should be of a sufficient wattage to ensure that the space is adequately illuminated for safety and comfort. 

In order to ensure that the bunker is as safe and comfortable as possible, it is important to develop a lighting plan that considers all the different types of lighting available. 

Task lighting should be used in areas where specific activities will be taking place, ambient lighting should be used for general illumination, and accent lighting can be used to add atmosphere and focus attention on certain elements. 

All lighting should be of sufficient wattage to ensure that the bunker is adequately illuminated for safety and comfort. 

By taking the time to carefully select the right type of lighting for a bunker, it is possible to create a safe and comfortable environment that is perfect for whatever activities will take place within it.

By the way, here’s our complete guide on building your DIY storm shelter.

2. Survey the Land

Once you have determined your needs, you will need to survey the land where you intend to build the bunker.

Surveying land for a bunker is an important step in the planning process for the construction of a bunker. 

It is important to make sure that the bunker will fit into its intended location without any issues, and that it can be safely and securely constructed. A thorough survey of the land should be conducted in order to ensure that the bunker can be built without any issues. 

Steps for Surveying Land for a Bunker 

When surveying land for a bunker, there are several steps that should be taken in order to ensure that the land can be safely and securely used for the construction of the bunker. 

  1. Establish a Base Line: The first step in surveying land for a bunker is to establish a baseline. This should be a straight line that is drawn across the land that will be used for the construction of the bunker. This line should be measured carefully and accurately in order to ensure that the bunker will fit properly into its intended location. 
  2. Mark the Bunker Location: Once the baseline has been established, the next step is to mark the precise location of the bunker. The bunker location should be measured and marked carefully in order to ensure that the bunker will fit properly into its intended location. 
  3. Map the Bunkers Location: Once the bunker location has been established and marked, the next step is to map the bunkers location. This should be done using a map or other geospatial data. This will allow for the bunker to be accurately located within its intended location.
  4. Survey the Land: The next step is to survey the land for the bunker. This should be done using surveying equipment, such as a total station, a theodolite, or a GPS receiver. This will allow for an accurate survey of the land, which is necessary in order to ensure that the bunker will fit properly into its intended location.

Safety Considerations

When surveying land for a bunker, there are several safety considerations that should be taken into account.

First, it is important to make sure that the land is free of any dangerous or hazardous materials or objects. It is also important to make sure that the land is free of any natural hazards, such as floods, landslides, or earthquakes.

Additionally, it is important to make sure that the land is not subject to any humancaused hazards, such as contaminated water or air.

Lastly, it is important to make sure that the land is properly marked and labeled in order to ensure that no one inadvertently enters the bunker construction site.

Here are 7 simple survival shelters you can build today.

3. Select the Right Materials

Once you have surveyed the land, you will need to select the right materials for the construction of your bunker.

When considering the right materials for constructing a bunker, there are several factors to consider. The first and most important factor is the purpose of the bunker. 

For example, a bunker constructed to protect against a nuclear attack needs to be incredibly strong and resistant to radiation, while a bunker intended to provide shelter during a natural disaster must be built to withstand the elements. 

In addition, the location of the bunker should be carefully considered, as certain soils may not be suitable for a bunker or may require additional protection.

The second factor to consider is the budget. Although it is tempting to use the cheapest materials possible, it is important to understand that doing so may mean sacrificing safety in the long run. 

The cheapest materials may not be suitable for the intended purpose and may quickly break down, leaving the bunker susceptible to damage from outside forces. 

Additionally, more expensive materials may offer superior protection, providing better insulation and overall durability than cheaper materials.

When selecting materials for constructing a bunker, it is critical to ensure that all components are rated for the desired application. 

This means researching material ratings for the intended purpose and ensuring that all components meet or exceed the required standards. This includes items such as concrete, steel, and other bunker components. 

It is also important to consider the environmental conditions the bunker will be exposed to, as certain materials may be better suited than others.

In some cases, it may be beneficial to use a combination of materials to maximize the bunker’s protection. For example, a combination of steel and concrete may provide superior protection against both natural disasters and nuclear attacks. 

Additionally, adding insulation to the interior of the bunker can help maintain a comfortable temperature within and also help protect against radiation. 

Finally, adding a layer of protective coating to the exterior of the bunker can help prevent corrosion and provide additional protection against the elements.

The right materials and construction design can make all the difference when it comes to ensuring the safety of a bunker. 

While it is important to consider factors such as the purpose of the bunker, the budget, and local environmental conditions, the most important factor to consider is the material ratings and construction standards that ensure the bunker will be able to withstand the intended application. 

By carefully researching these factors and selecting the most suitable materials for the job, it is possible to ensure that the bunker will be able to provide years of protection for those in need.

4. Design and Construct Your Bunker

Once you have determined your needs and selected the right materials for the job, you will need to design and construct the bunker.

If you are building an underground bunker, you need to make sure that the structure is strong and secure. You will also need to pay attention to any potential risks that could pose a danger, such as water infiltration and the potential for flooding.

Building an underground bunker can be a complicated task, so you may want to hire a professional contractor or engineer to help with the process. This will ensure that the bunker is built safely and correctly.

The layout section of this article above covers some amazing options for designing your bunker.

5. Equip Your Bunker

food storage

Once you have built the bunker, you will need to equip it with all the necessary supplies and equipment.

The first step in equipping your bunker is to consider your specific needs and the size of your family. Think about what type of supplies you will need, how many people you will need to accommodate, and how long you may need to stay in the bunker. 

This will help you determine the size and type of bunker you will need, as well as what supplies you will need. 

Once you have determined the size of your bunker and the supplies you will need, you can start to purchase the necessary items. The most important items to consider are food, water, medical supplies, shelter, and clothing. 

When it comes to food and water, you should purchase enough supplies to last you and your family for at least three months. 

This includes canned foods, dried goods, and other non-perishable items. Additionally, you should purchase a water filter, as well as several cases of bottled water.

Medical supplies are also essential for any bunker, and should include items such as bandages, gauze, antiseptic cream, and pain relievers. Additionally, you should include a first-aid kit and any prescription medications your family might need. 

In terms of shelter, you should include items such as blankets, pillows, and sleeping bags. You should also include a tent, tarps, and a generator to provide lighting and other power sources. 

Finally, you should consider clothing. Depending on the size of your bunker, you may want to include several sets of clothes for each family member, as well as rain gear, boots, and hats.

In addition to these essential items, you may want to consider adding other items to your bunker. 

This can include items like books and games to help pass the time, tools such as hammers and saws, as well as a solar panel to provide power. You can also include items such as candles, flashlights, and batteries for lighting.

Try to stock enough supplies to last at least three months, as you may need to remain in the bunker longer depending on the situation.

It is also important to install any security systems that you need to protect the bunker from intruders. This may include surveillance cameras, motion sensors, or even alarm systems.

Additionally, you should also install a backup generator in your bunker so that you can have electricity when the power grid is down. Having a generator will give you the ability to power lights, appliances, and other necessary items in your bunker. 

Make sure to use a generator that is specifically designed for use in an underground bunker, as most standard generators may not be able to handle the unique environmental conditions inside a bunker.

6. Prepare for Emergencies

Having an underground bunker is useless if you dont have a plan for what to do when an emergency does occur.

To ensure that everyone in your bunker is safe and secure, you should create an emergency plan that includes evacuation routes and emergency protocols.

You should also consider installing a secure communications system so that you can stay in contact with your family and friends while in the bunker.

Final Words

Building an underground bunker is a complex task, but it is possible to create a safe and secure structure that can protect you and your family in the event of an emergency.

By following the steps outlined in this article, you should now know how to build an underground bunker that meets all of your needs. Good luck!

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