A container home is a dwelling unit built from recycled shipping containers, such as a cargo container or storage container. These shipping containers are typically made from steel and come in two standard sizes – 20 feet by 8 feet and 40 feet by 8 feet.
These containers can be assembled or stacked together to create homes of various shapes and sizes. Shipping containers are designed to be strong and durable, so that they can safely transport various types of cargo across sea and land. This durability is one of the major reasons for their newfound popularity as potential housing units.
Another reason for the rising popularity of container homes is that they are environmentally sustainable. Because these steel containers provide the basic framework for the house, less energy and traditional building material (like brick or wood) is needed.
On average, the United States imports more goods every year than it exports. One fallout of this trend is that thousands of shipping containers are discarded every year, taking up space in various ports across the country, because it would be too expensive to ship empty containers back to the sellers, who are based in different parts of the world.
According to the U.S. Department of Transportation, millions of shipping containers are left dormant in U.S. ports every year, adding to the global waste crisis. (This surplus has been slightly reduced due to a temporary shortage of shipping containers during the COVID-19 pandemic, though.)
Needless to say, recycling and reusing these containers is the need of the hour. We could, of course, simply melt them down to reuse the steel. However, this would require over 8000 kWh of energy, which makes it prohibitively expensive under most circumstances.
So, what’s the alternative?
In the past, recycled shipping containers have been used to build various structures, including schools, swimming pools, and restaurants. There is even a shopping mall in New Zealand that was built entirely from discarded shipping containers. Recently, architects and contractors have been using these containers to build small, affordable homes across the U.S.
The affordability of container homes has made them increasingly appealing in an age of stagnating wages and skyrocketing real estate prices. A container home usually costs much less than a traditional stick-built house, as less labor and building materials are required for the construction process. Depending on their size, design, and the level of customization, most container homes cost anywhere between $20K and $150K. This can help new homeowners live comfortable, mortgage-free lives.
How Are Container Homes Sustainable?
The sustainability of shipping container homes has made them popular among environmentally conscious homebuyers. So, let’s take a deeper look at what exactly it is that makes these homes so eco-friendly.
Reusing & Recycling
According to a report by the Cambridge University Press, up to 3 billion shipping containers are produced every year. The lifespan of an average container is about 12 years, and most spend at least some of this time sitting unused. Needless to say, this is a waste of space as well as steel, a material that requires a lot of energy to extract and manufacture.
Turning the excess shipping containers into housing units is one good (and useful) way to repurpose them. It minimizes the need to produce new building materials. Shipping containers can replace timber, clay, and other precious natural resources that are typically used for home construction. They can also provide a more sustainable alternative to concrete.
The top soil used to manufacture clay bricks in a nonrenewable resource, since the geological processes needed for the generation of clay usually take thousands of years. Furthermore, traditional timber-framed homes contribute to deforestation.
Most shipping containers are manufactured with standard dimensions that are already suitable for home construction. Therefore, repurposing them to make container homes is the environmentally responsible thing to do.
Stacking a few shipping containers and welding them together – with proper insulation and internal partitions – can get you a home that is as spacious and comfortable as any traditionally-built structure. So shipping container homes are a great way of reducing waste and optimizing the allocation of natural resources, all without compromising on the beauty or comfort of your living space. A single shipping container would make a fantastic accessory dwelling unit, or ADU.
Greater Energy Efficiency
Shipping containers can be melted down, allowing the steel to be reused. However, this is an extremely energy-intensive process. An electric arc furnace (EAF) or basic oxygen furnace (BOF) must be used to melt a typical shipping container.
The process of melting a single container requires about 8000kWh of energy, as mentioned before. Needless to say, generating that much energy would have a massive environmental impact, especially since the U.S. currently has thousands of discarded shipping containers waiting to be recycled.
On the other hand, repurposing a shipping container to build a dwelling unit requires only about 400 kWh of energy, less than 5 percent of what it would take to melt the container for steel. Container homes are clearly the more energy-efficient option.
However, you must pay close attention to home insulation in order to make the most of the energy-saving properties of container homes. Steel, like most metals, is an efficient conductor of heat. This means that without proper insulation, container homes will get incredibly hot during the summer and quite cold in winter. This would drastically increase the amount of energy required for heating and cooling the house.
This is why well-insulated floors and ceilings, and insulated paneling and wallboards, as well as effective, low-VOC sealants and primers are essential features of a sustainable container home. (Here’s our article 12 Ways to Insulate Your Container Home.)
Recent technological innovations, like polyurethane foam insulation and ceramic coating, have the potential to make container homes even more sustainable and eco-friendly than they already are.
The energy efficiency of a container home will also depend, to a certain extent, on the size and design of the dwelling. Smaller homes are more energy efficient just because there is less space to heat during the winter or cool during the summer. A small, simple container home would also take less time to construct, making it less energy-intensive.
Pros & Cons Of Container Homes
From an environmental perspective, container homes have several advantages. However, they also have certain drawbacks. We have created a list of these pros and cons, to help you decide whether or not they are the most sustainable housing option for you.
| Feature | Advantage | Drawback |
| Building Materials | Container homes are made from repurposed shipping containers. So they require fewer building materials and help save precious natural resources. | Shipping containers often contain volatile toxic substances like benzene, styrene, and formaldehyde. Before a container can be used for housing, these toxic chemicals need to be removed or sealed, so as to prevent off-gassing. |
| Durability | Designed to carry heavy loads and resist harsh environments, shipping containers are extremely tough and durable. They’re resistant to corrosion and can withstand extreme weather conditions. Thus, less labor and materials will be needed to repair and renovate the home in the upcoming years. | The corrugation on the walls of a shipping container is essential for its structural integrity. Hence, when you cut an opening in the container for doors or windows, you’ll need to provide reinforcements. |
| Size | Shipping containers typically come in standard sizes that provide a little over 300 square feet of living space. Hence, container homes are usually smaller and more compact. Setting up a smaller home requires less energy and raw materials, which makes it more sustainable. | A container home can be made larger by stacking a few containers together. However, the relatively limited size makes it more likely that residents would want to move out as their family grows or they accumulate more belongings. This can lead to more construction and a greater impact on the environment. |
| Insulation | The relatively small size of most container homes means that they require less insulation, which helps save money and raw materials. | Steel is an efficient conductor of heat, which means that a container home can become unbearably hot during the summer, if not properly insulated. As a result, a lot more energy will have to be spent on air conditioning. |
| Age | Container homes are made from old and discarded shipping containers that have seen extensive use. Such repurposing and recycling can reduce waste, optimize the use of precious resources, and make home construction more sustainable. | Old shipping containers nearing the end of their lifespan often have scratches and dents that were made during their years at sea. They might also rust quickly due to their age. Therefore, they will usually need to be refurbished before being used for housing purposes. |
Maximizing The Sustainability Of Container Homes
A shipping container home can be a sustainable, cozy, creative, and affordable living space for you and your family. Every time a shipping container is upcycled into a home or other type of building, we reuse more than 3,500 kg of steel, and save a lot of energy that would otherwise have been used to melt the container.
Here are a couple of fun, green ideas to take a container home to the next level of eco-friendliness:
To maximize the sustainability of your container home, consider straw bale construction for better insulation. Straw bales have great insulating properties, with R-values up to R-35. You will simply need to build a small stem wall to add straw bales to the exterior of your container home.
By insulating your home with straw bales, you will be reusing a byproduct of grain agriculture that is often burned or left to rot. (Note: straw bales are best suited for use in dry climates—do your homework before you start construction!)
You can also plant a garden on the roof of your container home to provide some natural roof insulation. Shipping containers, with their impermeable and waterproof steel roofing, offer the perfect substrate on which to build a green roof.
You will simply need to add a pond liner to the roof, which will be topped by a growing medium like soil, encased in steel bars. You can then grow your favorite flowers and vegetables on the roof of your new container home.
Conclusion
Container homes are right at the intersection of affordable housing and sustainability, which makes them a winner in our book. We’re excited to see this trend increase as container homes become more mainstream.
I live in a container home and I’m loving it. If it’s done right, shipping containers is probably the sturdiest home construction you can do on a budget. However, I believe one has to be very careful not to get sucked in with the apparent “space for free” desire, by separating the containers and then filling in walls.
Unless you want to keep the space open and the roof structure is not too wide a span, you will have a bad surprise with the time and money needed to “contain” the space. For instance, the awesome (but expensive) Kalkin container homes. In my opinion, you need to keep the roof simple—let the container carry the load—once you need a wide span it becomes “involved” or “expensive.”
If you’re seriously considering building a strong, sustainable, affordable home using these highly sturdy steel building blocks, and in need of a reference resource that takes you step by step, try containerresidentiary.com Initially, I figured that container houses are spartan and would be very hot in the summer. But that opinion changed after I visited the house of a friend’s friend. I fell in love with the concept when I saw this structure as his living place.
And it wasn’t all that hot. In fact, the temperature inside was quite close to what you would experience within a concrete building because he had the heat insulation done right. He started this as his dream project and had actually completed the main structure, but for some reason, kept it aside for 2 years before reviving the project and finally finishing it some months later.