Are Container Homes Safe? Everything You Need to Know Before You Build

If you are interested in alternative housing, one of the first questions that you will have is, “Are Container Homes Safe?”

This is a legitimate concern, and the answer is yes! Provided that container residences are structurally designed correctly, container homes will have similar safety levels as traditional style concrete or brick houses (in some situations) but will offer superior strength.

When we discuss design, we mean the structure to be sound. Safety is not automatically created by the container; it is created through industrial design practices, specifications for structural materials, appropriate insulation, and compliance with local building regulations. Containerized homes have been constructed throughout over 50 countries by families, developers, and non-profit organizations as a permanent, safe, and sound solution to meet housing needs.

We have identified the major risk factors for container homes, including strength of structure, earthquake and typhoon disasters, fire and chemical safety, and longevity, so that you can make an informed choice about containerizing your residence.

Why Shipping Containers Are Structurally Strong

Shipping containers are designed to be very tough - they can carry tens of thousands of kilograms across the seas, endure being stacked nine units high, in constant exposure to salt air and mechanical pressure. Thanks to their industrial origins, they have a significant structural advantage when it comes to residential use.

Rather than using old containers that might have chemical residues or structural wear, ZN House uses new steel frames made of Corten, a type of weathering steel which is high-strength and naturally resistant to corrosion.

Are Container Homes Safe from Earthquakes?

Yes, and often more so than masonry buildings. Ductility is one of the major features that make steel an excellent earthquake-resistant material; steel will bend and absorb energy from a lateral load instead of fracturing and shattering like many other materials. Because of these unique properties, buildings constructed with steel framework have become the worldwide standard for construction resistant to earthquakes.

One of the advantages of container homes is their mass advantage. Compared to similar-sized concrete buildings, container homes are much lighter, thus applying much less force on the foundation during a seismic event than a similar-sized concrete building. Therefore, when container homes are located in areas with high seismic activity, such as the Philippines, Indonesia and Japan, the lighter weight of container homes provides a real safety advantage over similar-sized concrete residential homes.

However, engineered seismic safety must be built into the container houses. Some important structural requirements for container houses to be engineered correctly (to be suitable for earthquake loading) are: they shall be anchored to properly engineered foundations (not simply to lose piers); they shall have reinforced header beams on every door and window opening; and they shall have structural steel connections between stacked containers and between joined containers.

Container Home Safety vs. Traditional Construction

Are Shipping Containers Toxic?

This is indeed an important consideration. Used shipping containers are generally subjected to fumigation with pyrethroids; additionally, the wooden floors have most likely been treated with harmful preservation chemicals. The interior may also contain residuals from previous cargo, whether agricultural or industrial.

ZN House eliminates this concern completely due to the fact that new steel structures are used; therefore, there will be no fumigation residuals, chemically treated wood floors, or residual contamination due to prior usage; thus, ZN House will be safe for families and children from day one.

Fire Safety

Container homes have an advantage over timber-framed buildings in fire cases due to steel being a non-combustible material. The Corten steel frame/shell does not burn or carry flame. When there is a fire, the likelihood that the steel frame will maintain its structural integrity is much greater than that of wood.

Even though steel provides a safer living environment than timber, the interior still needs to be safe based on the specification of insulation, finishes, electrical wiring and appliances, which all contribute to the potential for fire and need to meet a minimum fire resistance rating.

If you’re looking to ensure safe, responsible transport of hazardous materials, you can visit the Dangerous Goods Containers page of MEOX.

What Makes a Container Home Unsafe?

Most of the safety problems that have been documented with container homes are caused by a few preventable causes:

Unengineered Structural Modifications

The wall's racking strength is then significantly reduced, making it dangerously vulnerable to wind and seismic loading. This occurs when large openings are cut for doors or windows without installing header beams and column supports.

Inadequate Foundation Design

Containers resting on loose earth or undersized footings are susceptible to differential settlement and connection failure during earthquakes or high winds.

Poor Insulation and Ventilation

Heat is transmitted and conducted through metal; however, without outside (exterior) or inside (air) insulation, polar temperature changes will occur within a typical building that will create condensation on cold steel surfaces which causes accelerated corrosion and mold growth on steel surfaces.

Low-quality Welding or Recycled Steel

Poor welds concentrate stress and can break under load at the connections that matter most

Non-compliance with Building Codes

All jurisdictions establish distinct sets of codes for wind loading, seismic zone location and corrosion exposure; violations of those jurisdictions create potential legal liabilities and liability insurers if any damage occurred as a result of failure to adhere to those codes or build with consideration for the environment in which you are doing business.

Extreme Weather Performance

How Long Do Container Homes Last?

A quality steel container home with a corrosion-resistant finish will have a minimum expected life span of 25 to 30 years, provided that proactive maintenance is performed regularly. Examples of proactive maintenance include resealing your container joints on a regular basis (e.g., every couple of years), applying a rust-inhibiting coating, and inspecting the entire container each year. With proactive maintenance, your container home will have a life expectancy of 40 to 50+ years.

Corrosion management in coastal areas requires more effort and diligence; however, using established marine-quality coatings will help to make corrosion management manageable.

Frequently Asked Questions

Are container homes safe to live in long-term, including for children?

Yes, these containers are safe when built using new steel, proper insulation and meeting the local code requirements. If you use new containers, you will not have to worry about any chemical contamination caused by fumigated or cargo-worthy containers.

How do container homes perform in earthquakes compared to brick or concrete houses?

Steel has a lot of ductile properties, which means that when an earthquake occurs, it can bend and absorb seismic energy instead of breaking apart. Because steel buildings are much less heavy, they also have less load on their buildings and foundations during a large earthquake.

What are the biggest risks with container homes and how are they avoided?

Engineering experts identify the major risks associated with a structural failure to include: unengineered openings; inadequate foundation systems; inadequate heat and sound insulation; and non-compliance with building codes, all of which can be avoided by engaging a manufacturer with verified engineering credentials and designing an acceptable structural solution from the beginning.

Visit the product page of our Container House Solution here.

Conclusion

Are container homes safe? Yes, as long as it has been engineered properly, there won’t be any issues with its safety. Issues such as fire, earthquake danger, being toxic, and not having a long lifespan arise not from having been manufactured as shipping containers, but rather to do with the fact that they were poorly constructed or unengineered conversions of an existing shipping container. A prefabricated container home, made from new steel, designed by a licensed structural engineer, insulated correctly, and built to comply with local codes, can give you confidence that the home you buy will be safe from any of the above issues. Your selection between a safe and unsafe container home comes down to how well the home was manufactured and how rigorous the engineering process was to support this manufacture. When considering the purchase of a container home, the most important questions to ask of your manufacturer are: A) Are you using new steel? B) Was the home designed by a licensed structural engineer? C) Have you addressed all local building codes and seismic requirements? If the manufacturer is reputable, they will be able to answer these three questions without hesitation.

Ready to build your safe, modern container home?

Contact ZN House today and get a free consultation from our engineering team.

Disclaimer: The technical data and specifications used in this document are based on ZN House's own manufactured products (containers). All specified information (specifications, materials, and technical information) of the manufacturer's products may differ based on project and location. Always consult a licensed structural engineer and follow local and/or regional building codes.