Underground bunker cost by type, size and add-ons
HomeGuide puts the cost of an underground bunker at $200 to $400 per square foot, or $40,000 to $80,000 for a 200 square foot shelter (HomeGuide bunker cost guide). Builders' own price lists spread much wider, since a bare steel tube and a finished shelter with air filtration, water tanks and power are very different jobs. This guide collects published prices by type and size, the site costs that often sit outside the sticker price, and a rough estimator.
Every figure here is the seller's or publisher's own, dated where they date it. Several exclude freight and installation, and we say so each time.
Cost by bunker type
| Type | Published price | What the price covers |
|---|---|---|
| Welded steel | $60,000 (8 x 12 ft) to $475,000 (14 x 50 ft, top tier) | Shelter only. Atlas says freight and installation are extra (Atlas Survival Shelters 2025 price list (updated May 1, 2025); Atlas Survival Shelters FAQ). |
| Corrugated steel pipe | $49,900 (10 x 25 ft) to $109,900 (10 x 51 ft) | An older, undated Atlas price page. The lower price in each range is a plain shelter with air filtration, blast hatch and escape tunnel (Atlas corrugated pipe shelters (older, undated price page)). |
| Corrugated culvert, partly finished | $35,000 | One new 10 ft by 30 ft culvert shelter with a door and wood floor, sold as-is, F.O.B. (Northwest Shelter Systems, culvert shelter listing). |
| Precast concrete | $25,000 (8 x 12 ft) | Shipping and installation not included. Comes with a CBRN air filter and a 32 x 32 inch watertight hatch (Bomb Shelter Supply, 8 x 12 ft precast concrete shelter). |
| ICF poured concrete | $800 to $1,200 per sq ft | Finished and installed, with an Andair VA150 filter. Utility hookups are priced separately (ExSpar bunker prices). |
| Shipping container | No reliable published price for a buried unit | Needs engineering and reinforcement before burial (Conexwest, burying a shipping container). |
One comparison deserves a careful read. ExSpar, which builds ICF concrete bunkers, sets a 10 x 40 ft steel bunker at $450,000 with shipping and installation against $360,000 for its own ICF version (ExSpar bunker prices). That's a seller comparing itself with competitors. Atlas lists a plain 10 x 40 ft steel shelter at $175,000 before freight and installation, and its more finished Platinum model at $225,000 (Atlas Survival Shelters 2025 price list (updated May 1, 2025)). Ask each builder for a written, installed price for your site.
Steel shelter prices by size
Atlas Survival Shelters publishes a full price list. These are its 2025 prices, updated May 1, 2025, for the shelter alone, without freight or installation (Atlas Survival Shelters 2025 price list (updated May 1, 2025); Atlas Survival Shelters FAQ).
| Size (ft) | Floor area (sq ft) | Basic model | Built Out | Platinum | Platinum Plus Plus |
|---|---|---|---|---|---|
| 8 x 12 | 96 | $60,000 (Garnado or Plain) | Not listed | Not listed | Not listed |
| 8 x 16 | 128 | $70,000 (Garnado or Plain) | Not listed | Not listed | Not listed |
| 8 x 20 | 160 | $80,000 (Garnado or Plain) | Not listed | Not listed | Not listed |
| 10 x 20 | 200 | $100,000 (Plain) | $125,000 | Not listed | Not listed |
| 10 x 25 | 250 | $125,000 (Plain) | $150,000 | Not listed | Not listed |
| 10 x 30 | 300 | $150,000 (Plain) | $175,000 | Not listed | Not listed |
| 10 x 40 | 400 | $175,000 (Plain) | Not listed | $225,000 | $300,000 |
| 10 x 50 | 500 | $200,000 (Plain) | Not listed | $250,000 | $325,000 |
| 12 x 50 | 600 | $225,000 (Plain) | Not listed | $300,000 | $375,000 |
| 14 x 50 | 700 | $300,000 (Plain) | Not listed | $400,000 | $475,000 |
Water storage rises with the trim level, from 110 gallons on the basic models to 300 gallons on Built Out and 600 on Platinum. The basic and Built Out models use a VA-40 NBC air system, and the Platinum models a VA-150. An escape tunnel adds $10,000 on the Garnado, Plain and Built Out models and comes standard on both Platinum models (Atlas Survival Shelters 2025 price list (updated May 1, 2025)).
Atlas quotes typical delivery at 3 to 12 months, depending on size. Rush orders add 10% to ship in under 12 weeks, or 20% for under 8 weeks (Atlas Survival Shelters pricing page).
Installation and site costs
Atlas suggests budgeting about 30% of the shelter price for installation. Its FAQ says installing a small shelter averages around $5,000, and a shelter of about 500 square feet runs $15,000 to $20,000. Atlas charges $125 per man hour for its own crew, and long-distance freight runs about $3 per mile (Atlas Survival Shelters FAQ).
HomeGuide's line items for a bunker project (HomeGuide bunker cost guide):
| Item | Typical cost |
|---|---|
| Delivery of a prefab bunker | $1,000 to $10,000 |
| Excavation | $1,100 to $5,600 |
| Tree removal | $150 to $2,000 |
| Building permit (large projects) | $500 to $2,000 |
| Running electricity | $1,200 to $7,100 |
| Gas line | $360 to $740 |
| Plumbing pipes | $4 to $5 per sq ft |
| Water heater | $600 to $5,600 |
| Septic tank | $3,500 to $8,500 |
| Appliances | $2,500 to $6,800 |
| Flooring | $4 to $15 per sq ft |
| Security door, installed | $400 to $800 |
| Security camera, installed | $125 to $450 |
HomeGuide adds that many prefab companies build excavation and installation into their pricing, so check before you stack these on top of a quote. Permit rules differ a lot by place, and the bunker permit guide covers how to find yours.
Air filtration, power and water
NBC air filtration
Most bunker builders fit a nuclear, biological and chemical (NBC) filter. HomeGuide notes that a cheaper HEPA filter may do if the shelter is only for natural disasters (HomeGuide bunker cost guide). Published prices for shelter systems:
| System | Price | Seller |
|---|---|---|
| ArcSafe 360 | From $2,999 | Bomb Shelter Supply |
| ARC VA-50 | $6,999 | Bomb Shelter Supply |
| Swiss NBC system | From $8,800 | Bomb Shelter Supply |
| Andair VA150 | $9,300 shipped | Utah Shelter Systems |
| ARC 180, floor mounted | $15,000 | Bomb Shelter Supply |
| Overpressure blast valve | From $700 | Bomb Shelter Supply |
Sources: Bomb Shelter Supply, air filtration systems; Utah Shelter Systems.
Power
Atlas describes three common setups: solar panels with a battery bank inside the shelter, an underground diesel generator in its own pod (for large shelters only), and a stand-alone propane generator above ground (Atlas Survival Shelters FAQ). Running power from the house costs $1,200 to $7,100 by HomeGuide's figures (HomeGuide bunker cost guide). Ready.gov's rule for generators is outdoors only, at least 20 feet from windows, doors and attached garages (Ready.gov, Power Outages). Ask the builder how a generator's exhaust is kept away from the shelter's air intake.
Water and waste
Water tanks are often built in. Atlas models carry 110 to 600 gallons depending on the trim level (Atlas Survival Shelters 2025 price list (updated May 1, 2025)). Ready.gov's guide is at least one gallon per person per day (Ready.gov, Water), so 110 gallons covers four people for about 27 days. A toilet adds plumbing and either a septic tank or a pump-out tank. HomeGuide puts a septic tank at $3,500 to $8,500.
Depth, soil and groundwater
HomeGuide says a bunker meant to protect against nuclear fallout should be at least 3 to 5 feet underground (HomeGuide bunker cost guide). Atlas says you need at least 36 inches of earth overhead for radiation shielding, and more depth to keep the temperature steady. It also warns against fields that flood and high groundwater. Fully welded steel shelters are watertight by its account, while its culvert shelters are waterproof but not watertight and shouldn't go in a high water table (Atlas Survival Shelters FAQ). Rock, deep digs and wet ground all push excavation costs up, so have the site looked at before you order.
Why a buried shipping container is a poor bunker
Containers can look like a shortcut. Conexwest, which sells them, says a standard container shouldn't be fully buried without professional engineering and major reinforcement (Conexwest, burying a shipping container). Its reasons:
- A container carries loads through its four corner posts. The roof and side walls are thin corrugated steel that was never meant to hold back soil.
- Soil on the roof can make it sag or collapse.
- Wet soil is heavier, and water trapped around the box adds hydrostatic pressure on the walls.
- Buried steel in damp ground can rust faster, which leads to leaks and mold.
Reinforcing, waterproofing, draining and engineering a container all cost money, so price that work before comparing it with a purpose-built shelter. Counties such as San Joaquin County, California, also require stamped plans for converted containers (San Joaquin County, California, cargo container permit requirements).
Rough cost estimator
Rough bunker cost estimator
Per-square-foot range, permits and site work: HomeGuide. Steel prices: the Atlas 2025 price list, using the cheapest model at or above your size, plus Atlas's suggestion to budget 30% of the shelter price for installation and its estimate of about $3 per mile for freight. ICF prices: ExSpar's $800 to $1,200 per square foot turnkey range, which includes the air filter. NBC filter range: the lowest and highest system prices listed by Bomb Shelter Supply and Utah Shelter Systems. This is a rough range from published prices, not a quote.
Common questions
How much does an underground bunker cost?
HomeGuide puts underground bunkers at $200 to $400 per square foot, or $40,000 to $80,000 for a 200 square foot shelter, with a national average of $60,000. Finished steel shelters from builders' price lists run from $60,000 for an 8 x 12 ft model to $475,000 for a large top-tier model, before freight and installation.
What is the cheapest type of bunker?
The lowest published price we found was $25,000 for an 8 x 12 ft precast concrete shelter, with shipping and installation extra. A partly finished culvert shelter was listed at $35,000 as-is. A shipping container looks cheaper, but it needs engineering and reinforcement before it can be buried.
How much does an NBC air filter cost?
Bomb Shelter Supply lists shelter air filtration systems from $2,999 to $15,000, with shipping and installation extra. Utah Shelter Systems lists the Andair VA150 at $9,300 shipped. Many steel and concrete builders include a filter in the shelter price.
How much does it cost to install a bunker?
Atlas Survival Shelters suggests budgeting about 30% of the shelter price for installation. Its FAQ says small shelters average around $5,000 to install, and shelters of about 500 square feet run $15,000 to $20,000. HomeGuide puts excavation at $1,100 to $5,600 and delivery of a prefab bunker at $1,000 to $10,000.
How deep does an underground bunker need to be?
HomeGuide says a bunker meant for nuclear fallout should be at least 3 to 5 feet underground. Atlas says you need at least 36 inches of earth overhead for radiation shielding and more depth for steady temperatures.
Can I use a shipping container as a bunker?
Not without engineering. Container seller Conexwest says a standard container shouldn't be fully buried without professional engineering and major reinforcement, because its strength is in the corner posts and the roof and walls can't hold back soil and water.
More reading: bunker vs storm shelter cost, bunker permit rules by state, fallout and EMP questions and a two-week home supply plan.
This is a general guide built from public sources, not engineering, medical or legal advice. Follow local officials during an emergency.
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