How to Build a DIY Underground Bunker and Survive SHTF

Nuclear fallout. The Black Death 2.0. A horde of hungry zombies clambering for your supplies.

You know what can protect you from all three? An underground bunker.

Underground bunkers (sometimes called bomb shelters, fallout shelters, or survival bunkers) are fool-proof ways to survive an apocalypse or two. But they don’t come easy; in fact, it takes a lot of effort, planning, and money to build a DIY underground bunker.

Curious about how to build a bunker that can put your old man’s Cold War bunker to shame? Read on:

A Brief History of Underground Bunkers

Humans have had a long history with subterranean dwellings, but the first “real” tactical bunkers were used back in World War 1. Most of these were located all over Europe and were used to house artillery and supplies.

After World War 2 and during the Cold War, underground bunkers were constructed as protection against possible nuclear attacks or fallouts. These structures had three things in common: they were underground, they were permanent, and they were, for the most part, indestructible.

Today, you can see many of these bunkers still existing around the world. British folks have their Anderson Shelters, which they built in their backyards during the Blitz. If you’ve ever been in Tornado Alley, you’ve probably seen one or two tornado bunkers. Heck, even China has a network of Cold War bunkers that they’ve now turned into cramped residential units.

Why You Should Get an Underground Bunker

Underground shelters have endured long bouts of war and peacetime, and for good reason: they’re built for survival. These shelters can protect you against a variety of natural or man-made threats.

Should you get a bunker for yourself? Here are a few reasons you might consider getting one:

Protection from Nuclear Weapons and Fallout

It’s been decades since the Cold War, but the threat of nuclear warfare still looms over everyone like a giant shadow. Countries like North Korea, Russia, and China have access to hundreds of nuclear weapons that they can launch whenever they please.

And if you think international law like the NPT (Nuclear Non-Proliferation Treaty) can shield you from nuclear warheads blasting you to kingdom come, you’re sorely mistaken. And ignorant to boot.

One of the few ways to survive a nuclear war and the inevitable fallout would be to stay in an underground bunker. Underground shelters are built to survive nuclear explosions, block radiation, and withstand the subsequent shockwave.

Hideout during War and Civil Unrest

If you’re unable to bug out, the next best option would be to hide in plain sight. Underground shelters built under unassuming backyards help you hide from looters and the zombie horde. It also protects you from a disease outbreak or biological warfare.

Protection from Severe Weather

The US experiences more tornadoes than any other country in the world, averaging about 1,200 tornadoes each year. And no, Dorothy, these don’t just happen in Kansas or Oklahoma. Tornadoes and severe weather can occur anywhere in the United States, so if you’re in their direct path, you might want to consider getting your own storm cellar or building a DIY underground bunker.

Extra Storage Space

If nothing else, underground bunkers make for excellent storage spaces. The temperature and humidity levels in underground shelters remain constant, protecting your food stash from spoilage. The absence of heat and direct sunlight also helps extend your supplies’ shelf life. As long as you keep it dry and clean, you wouldn’t have to worry about vermin and pests.

Potential Drawbacks of an Underground Bunker

Full disclosure before we start talking about your bunker options—living underground has its fair share of problems. Put serious thought into these and ask yourself if your household can handle things in an underground bunker:   

  • Limited entryways: Having a single entrance or exit is risky. If it gets obstructed, you may be stuck down there for good. 
  • Lack of space: Unless you’ve got the money to purchase an underground lair like Batman, you’ll be stuck in close quarters with your household. Everyone will be up in each other’s business.  
  • Accessibility: Getting in and out of a bunker can be tough for your family members with mobility issues. 
  • Flooding: This is one of the biggest dangers of a fallout shelter. Water from strong rains, hurricanes, or flash floods will make it to you faster when you’re below ground.  
  • Mold and mildew: Like basements, bunkers are prone to moisture. Your health will suffer a lot if you’re not vigilant about fighting mold and mildew.
  • Sewage: You can’t hold your poop or pee, but you also can’t just leave your sewage anywhere. How will you dispose of it?  
  • Psychological consequences: Being cooped up in a place with little sunlight and no windows can also take a toll on your mental health. Your anxiety can get triggered and there’s a chance you’ll fall into a depression.  

Should You Buy an Underground Bunker?

So you’ve weighed the pros and cons and decided that having a survival bunker is a good idea. Now what?

If you’ve got extra cash lying around, you might want to consider buying one of those ready-made underground bunkers for sale. These range from economy-sized bunkers with basic necessities like air filtration systems, beds, shelves, and plumbing to sprawling underground mansions complete with swimming pools.

There are companies out there who will evaluate the site, custom-build, or provide ready-made underground shelters that fit your needs. Here are some of them:

Atlas Survival Shelters

If you like watching survival bunker videos on YouTube, you’ve probably already heard of Atlas. Their videos have wracked up millions of views, and needless to say, they’re one of the most visible names in the underground shelter industry. They deliver and install bunkers worldwide.

The Atlas Survival Shelters website shows you what kind of shelters they can make for you, but you can also have yours customized to make it feel as homey as possible. To get a better idea of what one would look like on your property, the company encourages you to visit their headquarters in Texas. 

Rising S Company

Next up, we’ve got Rising S Company. Rising S and Atlas have a very public rivalry, but we’ll leave it up to you to decide which one is more worth your while. 

Rising S Company specializes in steel underground bunkers, storm shelters, and safe rooms. You can choose from the company’s existing floor plans, mix and match, or make upgrades where you see fit. 

Their most basic bomb shelter starts at $45,000, while the most expensive of Rising S’s luxury offerings will set you back a cool $9,602,500.  

Like Atlas, Rising S delivers and installs anywhere in the world. 


DEFCON is no stranger to building steel structures. They’ve constructed gantries, dam components, aerial walkways, and—of course—bunkers around the nation. 

The company has several pre-designed underground bunker plans to pick from, ranging from bare bunkers perfect for DIY to premium options with a water heater and solar charging. If you want, they can also build a fully customized shelter for you. Just check their site for more details. 


Don’t have any space to spare? You can buy a spot in one of the underground survival communities that have sprouted left and right in recent years.

Vivos, a company based in California, owns numerous bunker communities across the country and calls its network of underground shelters “the backup plan for humanity.”

The company acquired a former military base in South Dakota and repurposed all 575 underground bunkers found in the base into survival shelters. Each bunker in this community is worth $35,000 (plus yearly and monthly dues) and is equipped to house up to a couple dozen people.

Or Do You Wanna Build One Instead?

As you’ve gathered by now, most underground bunkers for sale don’t come cheap. They can set you back at least 30 to 40 grand. 

Excavation is another expense—this will cost you around $5,000 upwards, depending on the size of the shelter and where you’re located. Obtaining permits to install the bunker also isn’t usually included in the quote. 

If buying modular or ready-made shelters isn’t up your alley, you can always make a DIY underground bunker. A word of warning though: this ain’t some backyard fort.

Are we going to teach you how to build it, though? Hell yes.

In the next section, you’ll find factors you need to consider when building your own underground shelter:

What Should You Consider When Building a DIY Underground Bunker?

Deciding to build a DIY underground bunker is like investing in another house altogether, so you can’t do it on the fly. However, if the idea of having your own bunker excites you, here are some of the things you should consider:


Why are you building a survival bunker in the first place?

Is it for an impending nuclear war and the following fallout? Is your area at risk of an airstrike? Are you preparing for a long-term disaster or just need a space to protect you from severe weather?

Your bunker’s purpose will ultimately determine all the other factors that follow, so think about it.


Location is another crucial factor to consider when you want to build underground bunkers. It must have access to resources but must be relatively far from discovery. Ask yourself the following questions:

  • Can you build right in your backyard, or are your nosy neighbors such a huge risk that you have to build it in a more low-key location?
  • If so, how accessible is it? Can you get there by foot, or do you need transportation?
  • Is the terrain and soil condition ideal to support your bunker? (If you build in an area with lots of trees, for example, you’ll have a tough time dealing with the roots. Besides that, just think about its effect on the environment.)
  • Does your location have natural gas pockets?
  • How deep or shallow is the water table?

Bunker Size

How big is your DIY underground bunker going to be? How deep do you need to dig? Its size will primarily depend on your land area, but you should also consider the number of people occupying the bunker, the duration of your stay, the type of supplies you’ll be storing, and the overall bunker design.

Based on FEMA’s recommendations for tornado and hurricane shelters, at least 5 to 10 square feet per person is ideal.

Floor Plan and Layout

An efficient floor plan and layout are essential for your underground bunker. This should include:

  • Entrance and exit points
  • Living spaces (includes sleeping, cooking, washing, and toilet areas) 
  • Storage spaces for food, water, and gear
  • Mission spaces for communication
  • Important components like air and water filtration systems

There are dozens of available underground bunker plans online, which you can download or replicate for your own bunker. You can get inspiration from companies like Atlas and DEFCON or adapt plans for root cellars.

Here are other ideas you can use:

Septic Tank Storm Shelter

One of the easier underground bunker plans is a refurbished septic tank. Now you may already have a septic tank at home, but for obvious reasons (aka all that nasty toilet waste), you’ll need a new one to use as your survival bunker.

Luckily, a concrete septic tank is much more affordable than pre-made shelters from bunker companies. A 1,500-gallon tank costs around $1,700. You don’t have to be a math whiz to know that’s tens of thousands lower than the simplest shelter from Rising S!  

What’s also neat is that no one will suspect you’re building a bunker right under their noses. Your neighbors will just assume it’s an average septic tank—nothing out of the ordinary.

This article teaches you how to transform a septic tank into a legit fallout shelter.   

Concrete Shelter

Concrete can hold its ground against crazy natural disasters. It can withstand erosion, fire, and even radiation. The cherry on top? It’s affordable. Needless to say, it’s easy to see why concrete is such a popular construction material. 

If you’re gonna make your bunker out of concrete, however, you want the walls to be several feet thick so that it’s super heavy-duty.  


Here’s a neat shelter plan from the Department of Defense. This type of bunker uses bricks and structural clay masonry units. It’s designed to fit six people and can survive over 30 years if built well. The thing is, it’s best to construct this as part of a new house.

 Of course, you don’t have to limit yourself to these underground bunker plans. You can make your own floor plan and customize it according to your needs. Consider the rooms and facilities you’ll include and how to manage the limited space.


How much are you willing to spend on your underground bunker? The bigger your budget, the faster you can get the project done.

Still, even if you don’t have a lot of extra cash lying around, we don’t recommend that you pinch pennies when it comes to your DIY underground bunker.

Don’t go buying cheap materials, winging your own ventilation system, or opting not to hire a contractor even if you sorely need one. Unnecessarily cutting corners in the name of budgeting can bite you in the butt later along the way, so consider your budget seriously before breaking ground.

How to Build a Bunker

Okay, so we’ve gotten the basics outta the way. Let’s start making your DIY underground bunker.

Get Your Permits

The first step to building your own underground shelter is the least exciting part of it all: getting your permits.

Permits vary depending on your state and county, and they’re boring as hell, but you gotta get them to ensure that you don’t alter the local geology or potentially cause floods in your area.

Some permits you may need include:

  • Building permit: You have to secure this as proof that your survival bunker follows local, state, and federal laws.
  • Grading permit: If all the digging for your bunker disturbs the topography of the place, it’ll have to be graded. Before you even start excavating, a professional will have to assess the area to ensure your project is viable and that you aren’t harming any protected land.   
  • Discretionary permit: Certain states require this permit if a construction project may affect the surrounding areas because of its location or use. 
  • Plumbing permit: This is only necessary if your bunker is gonna have plumbing.

You should also call the utility company to make sure that you don’t hit any gas, water, or internet lines. You’ll be facing a hefty fine and the ire of your entire neighborhood, so be a trooper and just do it.

Secrecy should still be a priority, so if you’re not willing to disclose that you’re making a DIY underground bunker for the apocalypse, you can just say you’re building a wine cellar, digging a swimming pool, or installing a septic tank. You can even hire an out-of-town contractor further along the way to keep things on the down low.

Prepare Your Floor Plan and Bunker Design

prepare your DIY underground bunker floor plan and design

As mentioned earlier, there are tons of bunker blueprints and layouts available all over the internet. Take a look at any of them and see what best suits you. The important thing is to cover all the crucial bases like:

  • Viable exit and entrance points
  • Living spaces
  • Ventilation and exhaust systems
  • Drainage and sewage systems
  • Light and temperature control

You should also consider the design of your DIY underground bunker. You can choose from the popular round culvert pipe bunkers or go for the traditional, concrete-and-steel-plated square design. Each has its own pros and cons, so weigh those out carefully.

Regardless, most fallout shelters have L-shaped entrances to protect their inhabitants from gamma rays. Airtight inner doors are also the standard to keep noxious gases away and to make sure that the NBC filtration system works properly. Your doors also protect you from debris, fallout, radiation, and intruders, so make sure they’re strong. Preferably, they should be constructed from a steel frame and wood.

If you want to stay extra safe, you can construct your hatches from thick, hardened A500 steel, which is impervious to abrasions and bullets. Plus, it makes for a really badass entrance to the rest of your survival bunker.

Pick Your Materials

Concrete is literally a solid choice for your DIY underground bunker. It’s strong yet relatively affordable, plus it’s easy to work with. Combine it with steel, and you have a safe and sturdy underground dwelling.

Bricks are also a good option for your bunker walls, but you also have to consider that they take some time to lay down. We don’t recommend building your survival bunker entirely out of wood because of an itty bitty issue called decomposition. But you can incorporate hardwood in some aspects of your DIY underground bunker, as in the floors and finishings.

Get Digging and Building

A depth of at least 6 feet is needed for most underground bunkers, but of course, this would still depend on the scale of your shelter.

If efficiency is your top priority, you’d need to rent heavy-duty machinery to excavate the site. You might also want to hire a contractor to help you do most of the heavy lifting and installations.

If you’ve got some spare time, you can also dig your survival bunker the old-school way with a shovel. It takes a while and can be difficult when you encounter huge boulders, but it’s a cheap (albeit time-consuming) way to get things done.

Install Ventilation and Air Filtration

You need to find a way to filter clean air into your survival bunker. Installing an NBC (Nuclear, Biological, Chemical) Air filtration system is a must. This system sucks air from the outside and filters 99% of impurities like dust and bacteria with help from activated carbon.

It’s specifically designed for bomb shelters, so it can fight the effects of chemical weapons, biological aerosols, and other contaminants, too. NBC systems run on power, but they can be set up to automatically switch to backup battery juice, too. Here’s a great article that shares more information about NBC air filtration systems.

Aside from clean air, you also want to keep humidity low to let your DIY underground bunker stay dry, free from molds, and intact for many years to come. A dehumidifier comes in handy here as long as you have a sustainable power source. It’s also smart to install a thermometer and humidity gauge to monitor the humidity levels.

Secure Your Water System

man making adjustments to water pressure

You can’t survive without clean water, so it’s important to secure a reliable water system. Depending on how long you plan on staying in your bunker, this could range from storing gallons of water for your family until the threat passes to setting up long-term water acquisition and filtration systems.

For short-term bug-in situations, the standard is to store 2 gallons of water per person per day. For long-haul situations, it’s always best to have an underground water tank for a clean water supply.

You can also try to dig a well if your location and resources permit or use gravity to supply water to your cheap DIY underground bunker. Rainwater harvest systems are usually viable in most survival situations, but you don’t want to rely on them in case of a nuclear fallout situation.

Whichever system you choose, make sure to have a solid water filtration and purification process in place. A water system with a UV lamp allows you to purify large amounts of water at a time, but it doesn’t hurt to have backup plans like water purification tablets or iodine drops, too.

Establish a Waste Disposal System

Like your water supply, your waste disposal system can go two ways: you either can go full-on bucket brigade, or you can install a more elaborate waste disposal system as in a septic tank or a composting toilet.

We don’t recommend using buckets or paint cans as makeshift toilets, but if you’re going to go that way, make sure that they’re tightly sealed by lid or a sheet of plastic. You also have to ensure that they’re sturdy and won’t leak. Lastly, strategically place them near exhaust vents to help control the odor, or dig a waste disposal pit several feet away from your bunker.

The other options are less labor-intensive. You can include a septic tank to take care of your sewage and greywater. Composting toilets, on the other hand, work by evaporating waste material and turning them into compost. These systems are used in most off-grid homesteads and can work well for your bunker.

Aside from stocking up on freeze-dried food and other non-perishables, there’s also the subject of cooking. 

Assuming you’ll be in an enclosed space with little airflow, cooking with just any stove won’t be safe because of carbon monoxide. This gas will have a tough time escaping, and its fumes may eventually poison you.

You might have to live on canned food, jerky, and survival bars alone—you know, anything that doesn’t have to be cooked. Doesn’t sound appealing? Well, there IS a solution. Use an alcohol stove.

While alcohol doesn’t burn as hot as other types of fuel, it’s safe to burn indoors, and that’s really what matters most. You can choose between denatured, ethanol, or isopropyl alcohol (although denatured is best). Just take note that alcohol is highly flammable. Don’t keep your stove out of sight when you’re cooking, and stash your fuel in a secure place.    

Have a Solid Supply Cache

After you’ve stockpiled enough food for your family, don’t forget to load up on:

Power Supply 

If you’re planning to stay in your bunker long-term, you might want a way to generate power. You’ve got different options for this. You can go with a generator, try solar, or—if you live in a breezy area—wind.

Maintain Secrecy

Once your DIY underground bunker’s done, protect it from looters by hiding it in plain sight. Cover your bunker with several inches of soil to help ward off possible radiation.

Also, plan out how you’re going to conceal entrance and exit points from the outside world. A number of folks have hidden entrances in their main house, some cover the hatch with debris, while others hide entrance and exit points in plain sight by building sheds or outhouses over the entrance points.

How to Maintain Your Underground Bunker

You’ve built an underground bunker that rivals the Batcave. That’s awesome! But you can’t call it a day yet. There’s still the small issue of maintaining your fallout shelter. 

If you don’t want all your hard work—and money—to go to waste, then you’ll need to:

Look at the Structural Integrity

Wouldn’t it be ironic if the thing you built to protect you when SHTF ended up costing you your life? To avoid falling victim to a wobbly foundation or mold, check for cracks, leaks, and other forms of wear and tear every few months. Nip any issues in the bud ASAP. 

Inspect the Air Quality

Poor air quality can cause serious health problems down the line. Replace air filters and make sure your NBC air filtration system is still up and running. 

Get Rid of Expired Food

What good is collecting all that food if they just end up going bad? Remember to rotate your supplies and include your bunker when you check up on your emergency food provisions.   

Check Your Water Supply

The H2O in bottled water doesn’t go bad. But after some time, chemicals from the plastic bottle can leach into the water and harm your health. That’s why it has an expiry date. Keep tabs on this and replace your bottles if they’re about to expire. Do the same with water purification tablets.

If your bunker gets water from a well, then don’t forget to inspect it, too. It may get contaminated or completely dried up.

Final Thoughts

Once you’ve got all the components of your bunker figured out, it’s just a matter of building and installing them. Don’t have all your ducks in a row yet? No need to panic. A survival bunker is a long-term project and needs a couple of years to fully realize.

Knowing how to build a bunker is easier said than done, of course, but with patience and perseverance, you’ll have yourself a bunker that can protect you from the worst scenarios.

Already have a cheap DIY underground bunker underway? What’s your biggest challenge so far? Let us know in the comments below!

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