Underground Bunkers Shelters, Fortified Eco, Hardened Homes

View The Blog Index : 80+ Entries : Includes Contact Details.
Hardened Structures Operates Globally Including USA, Canada, South America, Europe, UK, UAE, Asia, Australia & New Zealand. Constructing a more secure future for you, your family, friends, corporates and governments. Make my enquiry to Hardened Structures. Email : Clarry@HardenedStructures.com.au www.Linkedin.com/in/IanClarry Hardened Structures USA www.HardenedStructures.com

Fortified Eco Hardened Homes : Chateau Pensmore, Ozark Mountains, Missouri : Geothermal Heat Exchanger


General Information
Type: Insulated concrete form
Architectural style: Châteauesque
Location: 2700 Woods Fork Road, Highlandville, Missouri
Coordinates: 36°52' 47" N93° 12' 45"W
Construction started: 2008 - 2013
Governing body: Private
Technical Details
Floor area: 72,215 square feet (6,709.0 m2)
Image Chateau Pensmore : Fortified Eco Hardened Homes

Pensmore is a mansion under construction in the Ozark Mountains of Highlandville, Missouri. When completed, the home will be the private residence of Steven T. Huff and his family. It will be one of the largest private single-family residences in the United States. Huff is the chairman of TF Concrete Forming Systems, which is doing the concrete construction work for the home. Huff at one time worked in Army intelligence and was a CIA officer. Huff later founded Sensor Systems in 1993 and served as its CEO. The company, later known as Overwatch Systems, created leading commercial software products for medical, defense and intelligence applications.


Steven T. Huff Family LLC applied for a construction permit in 2008 to begin construction of the mansion. The home is unique, as it is an insulated concrete form structure that is designed to showcase sustainable construction techniques on a large scale. The home is designed to be earthquake resistant, bullet proof, blast proof, tornado resistant, bug resistant, and fire resistant. The home is capable of withstanding an EF5 tornado.
The home will approach net zero on heating and cooling. Pensmore will utilize thermal heat collectors, a geothermal ground source heat exchanger, radiant heating and cooling, advanced climate control software, rainwater collection, and helix steel fibers.
Huff chose the location in Missouri because the state offers a climate that has both warm and cold temperatures, which allows for better testing of the green technologies in the home. Additionally, the rural location in Highlandville was known for lack of construction regulation. The project is not subject to building regulations or building inspections, which would have complicated construction efforts.


A variety of exciting new technologies allow Pensmore to dramatically cut energy costs without sacrificing practicality.
Pensmore's heating system utilizes a cutting-edge technique for harvesting solar heat energy that exploits the vast energy storage potential of its steel reinforced TransForm concrete shell. Many builders already make use of traditional solar heat collectors, which are highly efficient at moderate temperatures. But until now, it has been expensive and impractical to "bank" the excess solar heat generated on sunnier days. Pensmore's newly-developed technologies enable it to store millions of BTUs of thermal energy while the sun shines, slowly releasing this "green" heat back into the interior at night and during cloudy days.
Secondary sources of heat include combustion of wood products grown on the estate (net carbon neutral) and "conventional" geothermal systems.
Similarly, Pensmore's cooling system will make use of a unique technology that is both innovative and practical. We will be releasing more detailed information on the heating, cooling, and air conditioning systems in the future, so check back for updates as the chateau approaches completion.
Sustainability means more than just energy efficiency. It also means minimizing total life-cycle costs through low and zero-maintenance materials, and reduced use of non-renewable products during construction. Perhaps one of the biggest environmental advantages of Pensmore is its inherent durability. Designed to endure for centuries, the chateau will leave a minimum impact on the environment while other structures are built, demolished and built again and again.
Pensmore relies on the following systems and technologies:
  • TransForm: super-insulated energy-storing concrete forming system
  • Solar thermal heat collectors
  • Geo-thermal
  • Radiant heating and cooling
  • Advanced climate control software
  • Rainwater collection
  • Helix steel fibers
Pensmore is particularly noteworthy for its exceptional structural integrity. A proprietary TransForm concrete shell is reinforced with a special blend of Helix steel fibers by PolyTorx, making it highly resistant to extreme disaster conditions-including tornados, earthquakes, and even blasts. We believe these structural features will find application in some of the most turbulent regions of the world, where builders face unique challenges.
TransForm: TransForm is the next generation of insulated concrete form (ICF) technology developed by TF Concrete Forming Systems. Its versatility enables a builder to take virtually any architectural design and implement it with superinsulated concrete, optimally placing the insulation to take maximum advantage of the thermal mass effect. While several ICF systems exist on the market, many have steep learning curves, result in warped or out of true walls, and are prone to "blowing out" unpredictably on the job site as the concrete is poured into the forms. TransForm's patented design is simple for contractors to learn and use, and boasts new features that have virtually eliminated the "blow out" problem. Finally, the system is versatile enough to accommodate the complicated jogs and angles of Pensmore's French chateau design. TransForm allows even the most sophisticated architectural styles to be molded out of reinforced superinsulated concrete.
Helix: As a building material, concrete is extremely resistant to compressive forces. Still, most concrete structures need to be reinforced with special bars, grids, plates, or fibers for added tensile strength-particularly in high-stress environments. Pensmore™ accomplishes this with Helix steel fibers by PolyTorx: a reinforcement technology originally developed at the University of Michigan for earthquake and blast resistance in situations where rebar would simply not be enough.
As concrete is stressed or bent, rebar and ordinary fibers begin to fail after frictional pull out. But Helix fibers feature a unique "twist" shape that increases the frictional resistance-much like trying to pull a corkscrew from a cork without untwisting it. More importantly, the "twist" shape changes the failure mechanism from friction to a torsional mode. The additional force required is so large that the result is a performance level never before possible. This makes our structure more resistant to extreme weather and disaster conditions, allowing its concrete walls to absorb shocks and bend with them instead of breaking away from the steel rebar that reinforces it.
Concrete is one of the strongest and most durable known building materials in the world. Many Roman concrete structures built over two thousand years ago are still standing. By applying state-of-the-art technology to an ancient building material, Pensmore™ takes concrete building to the next level.

Building Pensmore

Comfort Design Inc. collaborates with Pensmore™ on its unique HVAC system.
Select individuals and companies have come together in collaboration to bring this living laboratory to life. On this page you will find information about these individuals and companies, and the roles they play in building Pensmore.

Core Technologies

TF Forming Systems developed and manufactures the TransForm super-insulating energy storing concrete forming system that is used to form the structural components of Pensmore. TransForm results in very straight and true walls of incredible strength.
Helix: The TF forming system can utilize any type of concrete and reinforcement. For Pensmore we use a combination of conventional steel rebar and Helix, a unique ultra-high performance steel fiber from Polytorx. Helix reinforces in all directions and makes the concrete much stronger and more elastic.
Andersen Corporation is the selected manufacturer of windows and doors for Pensmore. The developers chose products with Stormwatch® protection and SmartSun™. Specifically designed for coastal applications, windows with Stormwatch® provide added weather and security protection 24/7. SmartSun™ blocks 95 percent of UV light, which can be instrumental in reducing energy consumption and reduce fading of interiors. This combination provides a window and door solution that is both disaster resistant and energy efficient.
Meek's The Builder's Choice  is Pensmore's preferred source for building materials. We turn to Meek's to supply Andersen windows, roof LVLs, shingles, and more because of the personal attention they provide. We also utilize the unique tools at their one-of-a-kind design center.
City Wide Concrete is the Ready Mix plant that supplied the concrete for our TransForm walls. City Wide adds Helix steel fibers at the plant. Superplasticizers allow a very strong but highly pumpable mix.
Vulcraft supplied the steel joists and pan used to support the concrete deck floors of Pensmore.
Deville Steel supplied rebar and various steel components including beams and bearing plates.

10 : Silo Conversions

Beneath the grime, water and other signs of outward distress, many former nuclear bases and missile bunkers retain their top-notch construction achieved with the highest grade steel and concrete materials. Designed to last for generations, these locations can be inwardly and outwardly restored to provide unparalleled protection and security.
Hardened Structures has completed several retrofits of existing missile silos and telecommunication bunkers which include a private runway and helicopter landing pad, fiber optics, ventilation systems designed to detect and eliminate CBRN (Chemical, Biological, Radiological, Nuclear) contaminants, and a five star executive living interior.
These silos or bunkers, when fully retrofitted, offer single families or groups of families forming a survival community, exceptional survivability in a comfortable environment designed to client specifications.
Hardened Structures has available silos or bunkers in the following states which are immediately available to be purchased and retrofitted for any purpose.

9 : Genesis Series

The "NEXT GENERATION" of Underground Shelter Systems

The Hardened Structures "Genesis" series was developed for military applications and due to high customer demand for an Underground Shelter System that surpasses technical specifications offered by current shelter manufacturers to TRULY mitigate a wide variety of potential threats and disasters, including TEOTWAYKI (the end of the world as you know it) scenarios, while maintaining a very high level of safety and security.
To meet market demand, Hardened Structures formed a special design and engineering team comprised of leaders in the field of Structural Engineering, Electrical & Mechanical Engineering, EMP, Systems Engineering, and Architecture. This specialized team took over 6 months to design the NEXT GENERATION of Underground Shelter Systems called the "Genesis" series.
The "Genesis" series represents the strongest, safest, best designed and built Underground Shelter System in the world. Features include:
  • 3 Bar blast overpressure protection
  • Multiple Seismic Events
  • 100% waterproof
  • Blast doors
  • Fully Protected against EMP (Electromagnetic Pulse) and HEMP (High Altitude Electromagnetic Pulse). Fiberglass shelters cannot offer EMP/HEMP protection, see more at the bottom of the page.
  • 100% rust resistance (zinc anodes)
  • The best military grade NBC (Nuclear, Biological, Chemical) air filtration system available in the world (Temet)
  • Integrated emergency escape hatch
The Genesis Shelter System can be expanded to unlimited occupant loads and delivered and installed almost anywhere in the world. The "Genesis" series incorporates a modular approach .There are four main components to the Genesis series that can be purchased separately or combined together to form a Genesis community configuration:
  • Living Pods
  • Central Gathering / Dining Pods
  • Power Pods
  • Central Dome
Single Genesis Living Pods can be purchased to suit small families offering a very high level of safety and security.

To increase capacity or to offer a separate living, eating, and central gather area, the Genesis Gathering/Dining Pod can be added, thus increasing space and comfort for prolonged usage periods. This is a very serious consideration to examine when purchasing an Underground Shelter System.
By adding numerous Genesis Living and Central Gathering/Dining pods, safety and comfort can be provided for a small community.
The following pictures provide a realistic view of the interior space of the "Genesis" units. Interiors can be easily re-designed to accommodate client specific requirements. The technical specifications will not change, only the interior layout.

The Genesis Living Pods can be added to the Genesis "Dome" - thus offering a very comfortable, spacious community accommodating between 50 to 150 people and can be connected in series to allow for an unlimited number or occupants. The Genesis Dome offers the very same technical specifications as the Genesis Pods to form a community that offers safety and security unparalleled by any other shelter product in the world.
By adding on an additional Dome and Living Pods, this community can easily grow to 500 to 1000 people for durations in excess of 8 years - offering a true TEOTWAYKI structure built in 1/3 the time it would take for a custom design and construction. This benefit alone will make the Genesis Series the product of choice for the residential, commercial and military markets.

Stand alone Dome PG1 Stand alone Dome PG2

Several fiberglass subterranean shelter manufacturers claim that their shelters are HEMP/EMP protected and are MIL-STD-188-125 and MIL-HDBK-423 compliant. THIS IS NOT TRUE! If your shelter is not comprised of a conductive surface (i.e. metal) then it CANNOT be HEMP/EMP protected.
Electromagnetic fields pass right through fiberglass without attenuation (indeed – many antenna coverings and radomes are actually MADE OUT OF FIBERGLASS – because electromagnetic fields pass right through them! Even if painted with conductive coatings, fiberglass shelters will not protect you against EMP threats.
If you are considering a fiberglass shelter, then you are eliminating any possibility of protecting yourself from an EMP, because an EMP shelter has to be specifically designed and fabricated out of metal (preferably steel, for low-frequency performance) with each and every penetration engineered to keep out EMP energy.
This is why Hardened Structures provides quality steel enclosures - so that we can protect you from as many threat scenarios as possible – including EMP threats.
If you are going to invest in a shelter, ONLY a quality Hardened Structures steel shelter can protect you and your family from a broad spectrum of disaster scenarios that includes HEMP and EMP protection.
Do your homework on HEMP/EMP protection - here is what the U.S. Military; MIL-HDBK-423 specification says about HEMP/EMP protection:
The HEMP/EMP shield serves three functions as part of the EMP barrier:
  1. It prevents potentially damaging radiated electromagnetic stresses from an EMP event from reaching sensitive equipment inside the protective shelter by field reflection and attenuation (HS Comment: this is something fiberglass cannot do).
  2. HEMP-induced transients on exposed metal pipes and electrical conductors are deposited on the outer shield surface by the actions of point-of-entry protective devices and prevented from entering the protected volume by the skin effect – (HS Comment: whereas with a fiberglass shelter - the energy is conducted right INTO your shelter through pipes and wires and into your sensitive equipment!)
  3. The conductive shelter shield limits the number of ways that electromagnetic energy can enter the facility. (HS Comment: With a fiberglass shield there are unlimited ways in which electromagnetic energy can enter the facility)
The conductive steel shield is the primary element of the electromagnetic barrier. The shield, exclusive of the penetrating conductor and aperture treatments, consists of the metallic enclosure portions of the electromagnetic barrier. The role of the shield is to exclude electromagnetic fields from the protected volume of the facility. The conductive shield acts to reflect the incident fields and severely attenuate those fields and currents that penetrate into the metal. (Comment: in other words, fiberglass cannot be an EMP shield!)
To be effective, the shield must exclude or greatly attenuate incident electric and magnetic fields. To accomplish this, electromagnetic shielding surrounds a volume with a conductive layer that is thick enough so that highly-mobile electrons can arrange themselves and produce surface currents and charges that oppose the incident fields. This is the Faraday cage principle. External electric fields perpendicular to the surface are terminated on surface charges that form on the shield as its free electrons respond to the incident field. The tangential electric field is shorted and reflected by the conductive shield. Magnetic fields perpendicular to the surface induce eddy currents in the shield's surface. This, in turn, produces a magnetic field that opposes (i.e. "cancels") the incident field in and beyond the shield (inductive magnetic shielding). The tangential magnetic field induces current on the shield, which in turn produces a magnetic field that adds to the incident field (field doubling). (HS Comment: The end result is that with a steel EMP shield – you are fully protected from an EMP, with a fiberglass shield YOU ARE COMPLETELY VULNERABLE TO AN EMP)
The essence of a good shielding layer is the maintenance of good electrical conductivity, or low resistance, over all portions of the surface. Leakage through a shield surface occurs to the extent that voltages develop across resistances or impedances in the surface, and these voltages act as sources to reradiate fields into the interior of the shielded volume. The bulk of the shield surface will be made up of metal sheet. (HS Comment: Fiberglass has high-resistance over all portions of the shield – it optimizes the transmission of EMP energy into the shield enclosure!)
From MIL-STD-188-125-1:
"4.3.1 Facility shield. The facility HEMP shield shall be a continuous conductive enclosure (i.e. NOT FIBERGLASS) that meets or exceeds shielding effectiveness requirements of this standard. The shield is normally constructed of a metal, such as steel or copper. Other materials may be used if they can provide the required shielding effectiveness and are fully compatible (HS Comment: Fiberglass is NOT compatible, nor can it ever be made compatible) with the Point-of-Entry protective treatments and grounding requirements."
Listen to the company with Professional Engineers that build HEMP/EMP protected shelters for the U.S. Military!
Hardened Structures STRONGLY recommends that if you do not purchase a steel shelter that includes HEMP/EMP protection that you make sure you do not make a possibly critical error in your protection and survival plans and purchase a non-conductive fiberglass shelter – it could be the worst mistake you ever make and ruin even the most carefully thought out disaster preparedness plans.
Buy a steel shelter than can be configured to protect you against HEMP/EMP events, Hardened Structures will help you choose the right shelter for you, those important to you, and the components/equipment that will make your disaster preparedness plans work for you.

8 : Additional Sheltering Options

Extraordinary Engineering Solutions for Unique Challenges
Hardened StructuresThe Hardened Structures independent design and engineering teams have the unique experience and technical know-how to design, engineer, and construct specialized shelter systems in the most demanding environments and operational conditions anywhere in the world. We work closely with the client to understand their needs and design systems to mitigate any known threat.
Please review our web pages on the Genesis Series Shelter Systems, Concrete Dome Shelter Construction, and Missile Silo Conversions for examples.
Additionally we have experience working to dovetail Hardened Technology into both existing homes, and homes presently under design by custom design firms and exclusive architects. We are able to bring our team alongside you architect or designer to dovetail our technology into their design, without disclosing to the lead architect the technical specifications of our Hardening Technology.
Through our years of developing our technology solutions we have partnered with several key equipment vendors in life sustaining apparatus, and technological enhancements for the built environment. one such example is Hardened Structures partner for CBRN air systems. TEMET is our provider for world class blast protection and special ventilation technology applied in civilian shelters and hardened military shelters. TEMET protection technology is also successfully utilized in solving demanding protection problems in industrial and mobile collective protective applications. However we also have experience working with Andair AG USA, the US arm of the Swiss manufacturer of competing technology.
So whatever the project type, whatever the technical complexity, we have the experience and professionalism to accomplish you project.

7 : Underground Bomb & Fallout Shelters - Product & Services

Underground Shelters (aka bomb or fallout shelters)


"At Hardened Structures we design our civilian underground Shelters primarily for nuclear weapons of medium to large size but also secondary for chemical, biological and radiological dispersion devices and conventional weapons. Also known as Weapons of Mass Destruction or WMD's. Although the design and dimensions are principally determined for nuclear weapons it can be established that a good underground nuclear bomb shelter also offers excellent protection against chemical, biological and conventional weapons along with most types of WMD's. In addition, with the ever increasing importance of having EMP (Electro-Magnetic Pulse) protection of Shelters, and other "HARDENED" structures, we provide State of the Art EMP mitigation both in terms of Bomb Shelter design engineering, which incorporates EMP shielding, and the usage of specialized EMP components.
The extent of protection for private civilian underground bomb shelters will, in general, be determined by Blast Overpressure measured in "Bars", (where 1 Bar equals 15 psi of applied Blast Overpressure) and initial radiation mitigation. Protection against the penetration of chemical, biological and radiological weapons is achieved by constant positive internal air pressure maintained by artificially filtered ventilation and air-locks. At Hardened Structures we use only Military Grade NBC air filtering systems, blast doors, blast valves and other shelter components.

U.S. National Planning Attack Scenario

The United States National Planning Attack Scenarios have identified the detonation of a 10-Kiloton (KT) Improvised Nuclear Device as the most likely incident of a nuclear bomb exploding within this country. As a reference, the Hiroshima bomb was 12-KT and the Nagasaki bomb was 22-KT.
In this scenario a 10-kiloton improvised nuclear device is smuggled into the center of a large metropolitan city inside a delivery van and detonated. Casualties are estimated to be in the hundreds of thousands with infrastructure damage within a bounded range of effect of 1 to 3 miles. It is estimated that 1 million + people will attempt self-rescue by evacuating and contamination in varying levels will encompass approximately 3,000 square miles.
There are several websites which have info on potential nuclear targets within the USA and the subsequent fallout path.
Planning an Underground Shelter
To properly plan, design and construct a customized underground bomb shelter for our individual clients we must first:
  • Identify the threat levels; blast overpressure, radiation, etc.
  • Identify the assets to be protected; people, possessions, food, water, etc
  • Determine the length of the shelter duration
  • Thoroughly examine the site and geotechnical conditions
  • Be aware of all regulatory agencies having jurisdiction
Once this information is assembled a Protection Program and Cost Model Budget is then submitted to the Client for their review and approval.
Please contact Hardened Structures for additional information and to start planning your undeground shelter.


6 : Public Facilities, Utilities, & Infrastructure Hardening - Products & Services

Public Infrastructure

Department of State D.D.T.C. Registered Fully ITAR compliant for worldwide design and build services

The Hardened Structures team of specialized design firms and general contractors can provide Department of Defense designs or design/build services for almost any type of military facility including:

  1. Deep Earth Command and Control Bunkers
  2. NATO "Third Generation" Direct Attack Aircraft Hangers
  3. Earth Cover Magazines (ECM's)
  4. Hardened, Above-ground Blast & Ballistic Resistant Facilities
  5. EMP/HEMP Protected Facilities

The Hardened Structures team of registered architects, construction professionals and former Navy SEALS can provide the following services and products:

  1. Risk/Threat Assesments
  2. Red Team Assaults & Evaluations
  3. Architectural Engineering
  4. Shelter Dynamics & Programming
  5. Fortification Designs & Placement
  6. Structural Engineering
  7. Blast & Ballistic Engineering
  8. Mechanical & Electrical Engineering
  9. EMP/HEMP Mitigation Engineering
  10. CBRN (Chemical, Biological, Radiological & Nuclear) Air Filtration Systems
  11. Blast Doors, CO2 Scrubbers & Oxygen Machines
  12. Specialized Shelter Equipment
  13. Existing Facility Assessments & Recommendations

The Hardened Structures Team designs structures according to UFC 3-340-01: Department of Defense Unified Facilities Criteria : Design and Analysis of Hardened Structures and UFC 3-340-02: Department of Defense Unified Facilities Criteria.

Military grade pre-fabricated steel shelter systems. All designs meet or exceed the (USACE) United States Army Corps of Engineers design standards and are in accordance with the (IBC) International Building Code.

Complete design and specifications for Command and Control Centers, Continuity of Governments

  • Facilities, Communication Centers and similar Facilities.
  • Burster Slab designs and analysis. Full Blast Engineering and Mitigation designs.
  • Full Facility HEMP shielding designs and complete specialized component protection.
  • Military grade CBRE (chemical, biological, radiological and explosive) equipment including air filtration, blast doors, blast valves, etc.
  • Military grade pre-fabricated steel shelter systems, the GENESIS Shelter System

5 : Commercial Projects - Products & Services

Commercial Projects

Highly specific expertise for the commercial market

The Engineers and Architects who make up the Hardened Structures core team of professionals each have far greater years and depth of experience in commercial, institutional and government class projects than our background in hardened shelters for residential clients.

We see in throughout the entire sector of commercial building types and corporate campuses there is a need for higher levels of security infrastructures, physical security improvements, and planning for response to natural and made events to protect the assets and employees of corporations.

The physical improvements to the built environments need to be supplemented with standard protocols and procedures, trained to key staff to know how to react correctly to various types of events. To achieve this holistic approach to Security infrastructure improvements we have joined together with security consultants to integrate our services.

The approach to commercial building improvement requires meeting with our clients key stakeholders for interviews, surveying the facilities and preparing a written and graphic set of documents to recommend improvements.

These recommended improvements may take on much different aspects including but not limited to the following:

  • Modifications and or retrofit to the built environment, such as structural modifications and new spaces for secure purposes
  • Electronic monitoring
  • Perimeter security measures, electronic entry control, visual monitoring
  • Enhanced programming and training for applicable staff
  • Advanced telecommunications improvements
  • Standby and backup power planning

Commercial structures face differing levels of risk associated with CBRN threat, climate change and natural events, accidents or intentional (criminal or terrorist) events. The development of effective and efficient client/project-specific mitigation strategies requires the use of Risk Assessment. Risk is a combination of credible threats, vulnerability and consequence. Certain geographical areas have particular risk factors that affect facility capability need and placement such as population density, presence of critical infrastructure, location in a high terrorist threat or high natural disaster areas and military base/complex proximity.

Hardened Structures employs the latest Department of Homeland Defense and approved sensory and filtering equipment to protect commercial and government buildings. Hardened Structures is currently working to protect commercial and government facilities from the Mid-East to California.

The CBRN Threat

Counter-terrorism experts within the DHS, CDC, and NIOSH are vexed by commercial and public building vulnerability. An office building has a high concentration of human life encapsulated in a small space; an ideal target for today's merciless terrorist. The experts repeatedly identify the HVAC system as the most likely distribution point for a toxic attack.

Structural Hardening of Buildings and Structures

Innovative structural solutions are needed to "harden" new or existing commercial structures to accommodate client priorities. The Hardened Structures Team of specially trained independent design firms and general contractors has the required experience to design, engineer, and manage the construction of these specialized projects.

4 : Fortified & Hardened Homes - Products & Services

Fortified & Hardened Homes

Hardened Structures is a Professional Design & Construction Program Management Firm specializing in the confidential planning, design and covert construction of fortified homes (or conventional homes) with underground shelters or bunkers (shown above), stand alone shelters and other types of sheltering options. These facilities are designed with independent sources of power and water. They can serve as a primary dwelling, vacation home, retreat, long term shelter or expanded multi-function compound. Client confidentiality and total project secrecy are paramount on all of our projects.
Our Team comprises of a core group of independent design firms and general contractors with specialized training in the unique design and construction requirements of Fortified Homes.

Balanced Survivability Design Approach

Because it is impossible to protect against all threats and hazards, adopting a "balanced approach" in designs that considers intended functions, threat mitigation, and budget, is imperative. This is where Hardened Structures experience and know-how separates our Team from the general purpose Architects and Engineers. Our Teams experience has shown there is no one-size-fits-all or formula of security features and programs that will ensure 100% safety against all manmade or natural disasters.
In order to meet our client's goals and budgets, our Team ensures each project is designed and specified to meet a particular hierarchy of anticipated threats, not all possible threats. In other words, Hardened Structures' Team designs your facility to achieve a Balanced Survivability, ensuring that no one system or component is the "Achilles Heel". No matter if your personal threat hierarchy focuses first and foremost on a regional natural disaster, Nuclear, Biological, Chemical or EMP/HEMP event, or forced/armed entry; our experienced and highly specialized team of engineers, scientists and ex-Navy SEALS can confidentiality design and covertly construct your facility efficiently and cost effectively.

Traditional American executive home architecture has a number of pitfalls which are detrimental to secure home planning.

We can advise some sound planning principals for hardened home design which are contrary to the typical executive home plan, but very favorable to making the home much more ready to protect families in a crisis event.
One key design concern is a master suite separated far from children's bedrooms, often on the opposite site of the home, past the main entry, combined with a grand open plan main entry to great room layout ( 70% of home invasions occur through the front door ).
All humans natural reaction is to personally go secure their children in an emergency.
Therefore one can easily see how a home with the master and children's bedrooms separated by the main entry is a major design flaw in secure home design in event of a home invasions, (or even in a tornado or fire or earthquake).

Fortified And Hardened Homes

Secure And Elegant Fortified Homes

At Hardened Structures our architects can design to your individual architectural style be it Contemporary, Traditional, Colonial, Mediterranean, Beach Front, Southwestern or any personal preference.  We can also work with your own architect to achieve the level of protection and perfection necessary for your personal residence.  Our security consultants are internationally recognized experts in the fields of building fortifications, personal security, advanced security systems and offensive/defensive components.

At Hardened Structures we employ a Multi-Hazard Engineering methodology that not only recognizes individual threats sequentially, but also address all hazards/threats as simultaneously occurring, so as to insure there is no "Achilles Heel" within our designs.  The Protection Program for a Fortified Home is varied and is usually determined by the Client's Threat, Risk and Asset assessments.
The home can be protected against a wide range of threats including forced entry/assaults, climate change, chemical / biological / radiological / explosive (CBRE) agents, air-blast, ground shock, penetration, fragmentation and damage to the structure and equipment due to explosive loading.  Along with the Client's particular living, function and storage requirements, the designs also incorporate active offensive and defensive components, and mechanical responses to reduce the effectiveness of any given threat while providing for individual/family long term living requirements.
For most of our clients, one of the most important aspects of designing their Fortified Home is that it not resemble a fortified home and that the outwardly appearance is of a well designed custom home.  Only the owners will know the true capabilities and functions of the home which may include:

  • Vaults for firearms and ammunition
  • Vaults for precious metals, cash and other vaulables
  • Remote control Offensive and Defensive systems
  • Hidden compartments and sliding bookcases
  • Emergency escape ways
  • Alternative energy and sustainability systems
  • Vehicle storage and fuel systems
  • Ballistic walls, windows and doors
  • Fire resistance
  • "Off Grid" electrical capabilities
  • Independent water and sewage
  • Advanced security systems, CCTV, sensors and alarms
  • Hidden passages and entrances
  • Underground bomb shelter and storage

Meet The Team : What To Expect When Planning A Hardened Structure

This article is written by Douglas Clark from Hardened Structures for people who are considering building their retreat with a fortified shelter. Here, we will thoroughly explain the entire process on the shelter design and construction phases with our design professionals (engineers and architects) and other building industry professionals (general contractors, subcontractors and product vendors, etc).
Planning A Hardened Structure ImageBecause it is impossible to protect against all threats and hazards, adopting a "balanced approach" in designs that considers intended functions, threat mitigation, and budget, is imperative. This is where Hardened Structures experience and know-how separates our Team from the general purpose Architects and Engineers. Our Teams experience has shown there is no one-size-fits-all or formula of security features and programs that will ensure 100% safety against all manmade or natural disasters. In order to meet our client's goals and budgets, our Team ensures each project is designed and specified to meet a particular hierarchy of anticipated threats, not all possible threats. In other words, Hardened Structures' Team designs your facility to achieve what we term 'Balanced Survivability', ensuring that no one system or component is the 'Achilles Heel.' No matter if your personal threat hierarchy focuses first and foremost on a regional natural disaster, Nuclear, Biological, Chemical or EMP/HEMP event, or forced/armed entry our experienced and highly specialized team of engineers, scientists and ex-Navy SEALS can confidentiality design and covertly construct your facility efficiently and cost effectively.

What to Expect when Planning a Hardened Shelter with a Professional Team of Engineers and Architects

In most of the American Redoubt rural areas, you are not required to have a licensed architect or professional engineer to design your own home. Your local contractor can often provide you with a drafting service to plan homes, that is, if you only need to build a modern, code compliant home, up to about 3,000 square feet, with very modest improvements to perimeter security.
Please understand first and foremost that your project type will cost more than the standard level of construction.

In general, the costs associated with a custom project, both in terms of the professional design fees and the resultant construction costs, are much higher. For example, if the cost of new construction in your region is typically $140 per square foot for a nicely upgraded home of about 2,000SF, for a custom hardened and fortified structure, you can expect the costs to exceed $250 per square foot, or more, depending upon the threats you wish to be protected against. Some costs can reach over $800SF, depending upon the threat that requires mitigation.

The reasons for this are myriad, but it all stems from the multiple aspects of life support/life protection which must be achieved for a hardened shelter to be truly sustainable. For example, if one wishes to ride out a nuclear or biological event, that person is often seeking to be protected in the shelter for a period of a month, or longer.
A system MUST be in place to provide a continuous supply of clean air, and keep contaminated air from entering. This is one of the key lifesaving technologies needed to be employed in any shelter and is often referred to as CBRN (Chemical, Biological, Radiological & Nuclear). But this system requires extensive engineering, planning and a source for continuous energy as well as competent construction techniques. How are we providing power? If it is by generator, how are protecting the generator from sabotage or routine failure, proper venting and noise solutions? Our engineers have proven solutions for this, but they come at a cost.
Another cost consideration to balance is if the event we are protecting against is nuclear blast, what about HEMP? HEMP often coincides with a nuclear event. HEMP events disrupt and/or disable many electronics and therefore the shelter's energy source and the air pressure/filtration CBRN system must also be HEMP protected. Possibly other living spaces need HEMP protection, but this should be kept to a minimum if budget is a constraint.
The two technology fields of CBRN (air filtration and overpressure), and HEMP shielded enclosures must be planned in unison. Any unplanned Utility penetration in an HEMP shielding solution will cause the HEMP shield to fail. However, these engineering specialties are each the work of separate professional engineers, which must be coordinated by an experienced project manager.
Additionally, the logistics of calculating and planning an ample source of energy, with fuel, is a very costly undertaking. While you are in this shelter, you will need to prepare food, drinking water, maintain human sanitation, and be in an environment which does not drive you or your group members into emotional issues. You are essentially taking 21st century first world civilians and placing them in harsher conditions than we place highly trained and rigorously screened candidates for the US Navy submarine fleet. This is not to be underestimated; FEMA guidelines for disaster shelters are rumored to have been developed with an acceptance of a 10% suicide rate. What is the acceptable suicide rate for your sheltering group? If it is less than 10% then we would like to plan your shelter with more comfortable amenities than you would have in a FEMA specification quality of shelter.
In short, You simply cannot have a nuclear blast protected bunker which can sustain your family in a post apocalyptic event, for months and months, with air filtration, generators, water, food, storage, and hardening against small arms up to .50 BMG for the same price a standard home.

Generally, this is the point at which some potential clients depart from engaging our services. The projects we work on are usually over a half million dollars. This is not to say a lesser-cost project is impossible, but the challenges increase, and it does cause the design and engineering fees to become disproportionate to the project cost. For a project over $500k, the complete design and engineering package is roughly 10-12% of construction costs. For projects of $250k and less construction budget, the engineering costs do not come down in equal proportion to construction costs, and can exceed 15% of construction budget.

But what about those bunkers that are made entirely out of metal that you can find on the Internet for $39,990? Sure, these will work well in a very short-term scenario, but at what cost? If this is all you can afford, then it's better than nothing, and certainly well worth the price. However, some considerations should be noted from an engineer standpoint;
These may offer some utility in a certain scenario for a very limited duration; you can do your own research regarding the depth of soil cover required for plate steel to be enough to stop gamma waves (nuclear fallout). Be sure to confirm weight of the depth of fully water-saturated soil needed does not exceed the strength of the steel box. Is the price advertised inclusive of shipping, excavation, and utility infrastructure? If you need a place to go hide during the next LA riots and can be very sure no one will find and disable your source of electricity and/or water, you could be ok in a metal box shelter. Also these types of structures are acceptable if you are looking truly for just a tornado shelter then FEMA guidelines on how to construct one are perfectly acceptable as well, for potentially even greater cost savings.
Beyond the hardened structure, every client also needs a longevity plan. That being a plan for what to do after the major event subsides and how to maintain an ongoing posture of security and to transition forward into a new lifestyle. This includes everything from considerations for permaculture, childrearing, or mounting an active defense against numerically superior forces. A sophisticated team for fortified shelter design will include security consultants and be able to help plan the steps to take to set up life post event, and include provisions in the design for life afterwards.
What to expect when planning a Hardened Shelter:
There are several pre-design steps one can take to begin conceptualizing what will be needed to meet your goals in a hardened structure.
These are listed below:
  1. You need to list the threats you are preparing to survive and then rank these in priority. These can be natural disasters, manmade events or others; this is your own list. A team will begin design to achieve protection for the most major event. By doing so, most often we find that we cover most needs presented by the threats further down the priority list, and we can make inclusion for those events in addition to the overall major planning criteria.
  2. Given the identification of the most major event to protect against, what is the longest you want to remain interred in the shelter without exiting the structure.
  3. You need to list the assets you are protecting, human assets and material assets. How many people is just part of the equation, who are these people, what are their individual special needs, and what is their relationship to one another?
  4. Where and what are the site specifications? The aspects of regional demographics, site topography, terrain analysis, soil type, the adjacency relationships of your site to its neighboring properties, roads, towns, military installations, power stations, waterways, seismic faults, all contribute to a complex site development analysis process to help determine how to best protect our clients.
  5. What are your group's abilities and limitations? This is an important criterion to really look hard at your entire group dynamics at the present and into the foreseeable future, and not based on the past. Maybe a member of your group has special medical skills. That training is most useful when provided with a facility and the equipment needed to perform those life saving skills. Or maybe someone in the group was a very accomplished athlete, but that was 20 plus years ago, or the person is most busy presently with small children who are also part of the group.
Given the identification of the most major event to protect against, what is the longest you want to remain interred in the shelter without exiting the structure?
Once these criteria are identified, they can be translated into performance goals for the Hardened Shelter, such as size, engineering and technology needed, and a list of spaces and special features.
Once this is determined, a team leader, architect, or project manager can then assemble the team of engineers needed to develop your Hardened Shelter. Also, this set of goals becomes a program statement, which you should receive from your design team, and review carefully. You should make sure all your needs are met in this program statement; otherwise, it is likely some of your goals for the shelter might not make it into the design. At this point, your designer may be able to communicate a rough conceptual budget for the project, based upon the program statement and his past experience with other projects. This early conceptual pricing statement has an accuracy of +/-20% because so much is not yet known with the design, and how the actual site impacts the cost of the project. However, it is very important at this early phase in the planning process that you check your goals vs. the possible budget for the project. This is the easiest time to readjust goals to align with your budget.
The adjustment of goals to match budget is a very difficult mental process for many clients, and here is another place where clients fall out of design services. Many folks just cannot get past the idea that if they cannot have everything they want for the budget that they had in mind, then the project is not worth doing at all.
This is not realistic thinking. We all make value choices in products everyday based on cost versus performance or quality. We do the best we can within our own priorities.
The important thing is to really look hard at your priorities from an aspect of most likely threat to protect against, and a worst-case threat you must protect against, and the minimum acceptable outcome of these two scenarios. With these goals as the guiding principles, often we can help clients focus on a budget that's realistic for the projects overall goals.
One example of this is duration of sheltering. Clients often come to us with the perception of a need to shelter continuously for many months. This criterion is very expensive to achieve both in terms of space required but also in logistics and energy provisions. However, there are alternatives to months of sheltering that can be considered and still have high expectations of survivability.
Once the design program aligns with your budget, your design team is able to move forward with planning your project.
This is an interactive process and you as the owner have a tremendous impact in the outcome. One temptation to resist is over designing. There are infinite possibilities in design, far more than there are choices in the marketplace when researching a new vehicle or appliance. However, exploring all of them is not realistic and it is important to remain focused on the goals of the project and accept standard construction practices as much possible.
With these concepts in mind, it is highly possible for you to be able to plan a Hardened Shelter with professional engineers which meets an adequate level of survivability metrics to ride-out many foreseeable SHTF scenarios, and allow you and your loved ones to emerge ready to take on the real challenges of life in the world after TEOTWAWKI.

HEMP/EMP Shielding

EMP Engineering can provide comprehensive and effective hardening, hardness verification and hardness surveillance of bomb shelters, buildings, facilities, hardened shelters, command/control centers, data processing centers and business continuity centers against the damaging effects of Electromagnetic Pulse (EMP), HEMP, GMS, or transportable High-Powered Microwave (HPM) weapons. The function of these facilities supporting critical time-urgent applications requiring network interoperability and effective physical protections, electromagnetic shielding, point of entry (POE) protection and related special protective measures. At EMP Engineering we offer cost effective solutions and full manufacturing capabilities for most any type of HEMP/EMP/GMS mitigated facility along with full hardened shelter design/build services. We are dedicated to the design and implementation of robust, hardened CBRN and EMP measures – including specialized shielding / mitigation, components and sub-systems, to prevent the harmful effects of intentional or unintentional Electromagnetic Pulses and Geomagnetic Storms.
To create a protective electromagnetic-threat facility shield requires an electromagnetic barrier with additional special protective measures that incorporate electrically continuous housings that substantially reduce the coupling of EMP electric and magnetic fields into the protected area. The electromagnetic barrier shall consist of the Facility HEMP Shield and protective devices for all POE’s. Additionally, reliability, maintainability, safety and human engineering, testability, configuration management and corrosion control all need to be incorporated to the HEMP protection system design.
To accomplish this goal, a Client specific Vulnerability identification/Hardness Program overview and criticality assessment must be conducted that incorporates design, engineering, fabrication, installation and ongoing effectiveness testing activities to achieve the following:
Provide an electromagnetic threat- protected facility or system design based upon verifiable performance specifications against identified threats that ideally suits the requirements of our clients.
Provides a means of verifying achieved hardness levels through a cost-effective program of testing and analysis.
Develop a maintenance/surveillance program during the procurement phase that supports the Client’s operational and life cycle HEMP hardness requirements.
Based on the anticipated threat, facility location and Client’s protection program establishes the HEMP configuration baseline consisting of documentation of the physical characteristics of the HEMP protection system, subsystem and baseline performance data. 

Interested in Hiring us?

By their very nature, hardened shelters and underground bunkers require highly specific life safety and threat mitigation features in order to perform their primary mission: protecting your family. This is not a job for the average architect or the common contractor. Success requires a unique expertise in HEMP/EMP, WMD’s, blast effects mitigation, adversarial assaults, shelter dynamics, threat mitigation measures, advanced HVAC systems, structural steel/concrete and earth work operations.
We mitigate various threats by employing a Multi-Hazard Engineering methodology that not only recognizes individual hazards/threats sequentially but also address all hazards/threats simultaneously as a problem of optimization under constraints. The facility/shelter/building can be protected against a wide range of threats including WMD’s, forced entry, armed assaults, climate change, chemical, biological, radiological, explosive (CBRE) agents, airblast, ground shock, penetration, fragmentation and damage to the structure and equipment due to explosive loading.
Our Spectrum of Services include:
  • Architecture and Programming
  • Engineering (Structural, Civil, Mechanical & Electrical)
  • Shelter Dynamics
  • Asset Value Assessment
  • Threat Hazard Assessment
  • Vulnerability Assessment
  • Full Risk Assessment
  • Red Team Assault Evaluation (Ex-US Navy SEALS)
  • Site Selection and Layout Design
  • Building/Site Design Management
  • Blast Effects and Mitigations
  • HEMP/EMP shielding
  • Chemical, Biological and Radiological Protective Measures
  • Ventilation, Air Filtration and Sorbent Filtering Systems
  • Sustainable, Alternative, Climatic and Solar Energy Designs
  • Budgeting and Estimating
  • Permitting and Local Jurisdiction Approval
  • Full Construction Contracting
  • Long Term Survivability, Food Storage and Equipment
  • Shelter Commissioning
  • Client Move-in and Start-up
As Professional Architects and Engineers, Security Specialists, Project Managers and Ex-Navy SEALs with over 30 years in shelter construction experience, our approach methodology is to professionally and confidentially complete the designs, and covertly construct the facility while ALWAYS working in the best interest of our Clients.
The Hardened Structures Team analyzes all options for shelter construction including concrete, steel, fiberglass or composites to find the best fit for our client’s unique shelter, sustainability and funding requirements and implement a design/build program for that particular client. Experience has shown there is no “one size fits all” when it comes to Shelter construction. Simply stated, we work for you as your private Facility Staff providing single point responsibility for the fast and efficient delivery of your Facility in a stealthy and secret atmosphere.
Our experience has proved that the basic fundamental rule necessary to successfully execute Covert Construction and Clandestine Contracting techniques is “Need to Know.” The level of secrecy is established by our Client and is a direct determinant affecting the overall cost.
Our services can range from complete design and build to working directly with your preferred architect and / or contractor to provide specific consulting services.
We can bring in our own specialized workers and we have perfected the protection process to ensure that no one subcontractor or supplier will fully know the final function or true capability of our Client’s facility. Some of the techniques we employ include:
  • Compartmentalized and Furtive Construction Scopes
  • Phased Critical Path Construction Techniques
  • Specialized Out-Of-Town Subcontractors and Suppliers
  • Multiple Surreptitious Project Identifications
  • Correlated CAD Drawings and Specifications
  • And Other Time Tested (and Secret) Clandestine Strategies


Table of Contents

1. Summary of Client Interview and Site Visit.

 a. Project Mission Statement

 b. Client’s threat concerns / Types of threats
   i. Human threat, motivations and actions, ballistic level
   ii. Natural threats
 1. Severe Storms, Hurricanes and Tornados
 2. Wild Fires
    iii. Geopolitical threats
    iv. Threat types excluded from design criteria.

 c. Client’s assets to protect. i. Human assets ii. Material assets

 d. Overview of The Site i. Size, location, maps, terrain, vegetation, climate, annual rainfall, average high and low temps, maximum storm forces. ii. Likely avenues of approach iii. Local crime activity iv. Proximity to military installations, nuclear targets, danger from storms

1. Nuclear Targeting and Fallout shadow a. Prevailing wind direction, average speed, resultant shelter –inplace recommendation. v. Supporting Statistics for Natural and Man-made Hazards

2. Recommendations
 a. Recommendations for the built environment
i. Hardened Home design program

1. Space programming list

2. Modern Home Design Aesthetic Examples

3. Hardened Technologies to employ in home design a. Forced Entry Resistance and Ballistic Protection b. Active Defense enhancements to design c. CBRN Air Filtration overpressure system d. Severe storm / high winds protection. e. Overlapping benefits of program requirements into other areas of threat protection.

4. Clean water, human sanitation. a. Well water systems i. Back up pumps ii. Tanks and gravity feed systems iii. Water source hardening and filtration. iv. Grey water systems

5. Energy Efficient Design Performance
 a. Passive House – German Derived Energy Efficiency Standards i. Insulation, air sealing and windows ii. Energy Recovery Ventilation with Whole House air filtration iii. Ductless mini-split heat pump systems iv. High efficiency water heating systems v. Wood Heat with integral or separate water heating/ radiant floor

6. Grid Tied Energy – Electrical energy hardening

7. Off Grid Energy a. Diesel and Gas Generators i. 1800 vs 3600 rpm models at equal KW ratings. ii. Preliminary Generator sizing fuel consumption rates and tank sizing b. Renewable energy sources, Wood, Wind, Solar, micro hydro etc. i. Wood gasification to run generators. ii. Hardened Shelter Design
1. Hardened Shelter Space Planning Program
2. Hardened Shelter Structural systems
3. Hardened Shelter Mechanical Systems
4. Hardened Shelter Electrical Systems

b. Recommendations for site development
i. Concentric rings of security concept and applications to client site ii. Site clearing/grading tactical and wild fire defensible space criteria. iii. Limiting likely avenues of enemy approach iv. Escape, evacuation, caches and counter offensives. c. Recommendations for site and for early warning/detection d. Recommendations for active and passive defense e. Recommendations for provisioning and training of group members

3. Preliminary Cost Model

4. Project Plan of Action

5. Overall Project Schedule

6. Concluding remarks

7. Additional references

8. Appendixes to report
 a. EMP Threat Summary Narrative

Hardened Structures Extensive Shelter Guide - Threat Assessment, General Space, Structural, Mechanical and Electrical Requirements / Components

Meet The Team

Douglas Clark at the 2016 Texas Grid Security Summit


NCT CBRNe USA IB Consultancy Image

Planning A Hardened Structure Image

Planning A Hardened Structure Image

Planning A Hardened Structure Image