Shipping Container Fundamentals

It’s incredible to think that something as pervasive and integral to the world economy as shipping containers didn’t even exist just a few decades ago. And then to think that, thanks to the ingenuity of a few forward-thinking individuals, we now see containers in a whole new light as building materials.

Shipping containers are special, but they aren’t perfect. Thanks to our years of experience, we can appreciate many of their great benefits while still recognizing where they can sometimes fall short. Thankfully, we also have insight on how to overcome many of these perceived negatives.

In this Article

Our intent here is to highlight the incredible rise of shipping containers into the world’s consciousness. We start by discussing the origins of containers: first as a method for transporting goods, and more recently as a means of building. Then we’ll discuss some of the pros and cons of using containers for your next construction project.

Shipping container housing has stormed onto the scene as a hot new form of architecture. These repurposed containers are an attractive option for all types of projects – from affordable housing that you can put almost anywhere to unique, modern spaces for commercial or multifamily use. But in order to get a complete idea of whether this building style is for you, we have written this article with a comprehensive look at what you can actually expect from these metal boxes.

Whether we talk you into using containers, or out of them, we’ll consider this article a success if you have a better understanding of the entire picture and can make the best, most informed decision for yourself.

History

The shipping container, like most new products, was created to solve a problem: how to transport goods quickly and safely across both land and sea. Of course, humans had been doing just that for thousands of years, but usually in ways that were quite inefficient.

The crucial innovation of containers was that they were:

  • Big enough to hold several thousand cubic feet of goods, but small enough to fit on a truck and drive on normal roads
  • Strong enough to survive an often treacherous journey at sea, but light enough to be moveable with cranes, forklifts, and other material handling equipment
  • Uniform enough that any truck or ship could hold any of the several sizes of containers available, but flexible enough that they could be used for dry goods, refrigerated goods, bulk liquids, etc.

Thanks to the work of people like Malcolm McLean, in just a few short decades, the world has been completely transformed by the economical transport of goods from distant countries. These steel shipping containers were the essential invention that made it happen.

Containers on a ship

Imagine if you could travel anywhere in the world and use the same type of electrical plug, or make purchases with the same currency. Achieving this level of standardization across the world is very difficult, but that’s exactly what shipping containers accomplished!

One thing McLean may not have foreseen was the buildup of excess containers over time due to trade imbalances. That and other factors led pioneers to explore transforming shipping containers into useful buildings in the 1980s. Today, thanks to the ingenuity of both professional designers and ordinary people just like you, we have thousands of examples of incredible container structures.

To learn more about the fascinating backstory of these cargo boxes, read our article on the incredible history of shipping containers.

What Are Shipping Container Homes and Buildings?

Contrary to what some may think, the category of buildings that fall under shipping container construction is quite large. Container architecture has almost become its own field, and architects around the world are showing just how innovative they can be with the same basic building blocks.

There are single-unit container cabins, container tiny-houses on wheels, and huge container homes built with adjacent walls removed for larger interior spaces.

containers on grain silos
The Mill Junction student apartments in Johannesburg, South Africa uses containers placed on top of old grain silos!

There are all manner of container hybrid buildings that blend containers with traditional construction including traditional buildings built on top of containers, containers assembled on top of traditional buildings, traditional buildings with containers inside of them, and traditional buildings with containers jutting out through them.

There are container buildings with exterior cladding and interior walls that make it effectively impossible to tell there’s a container underneath at all unless you were watching during construction.

There are containers arranged in uniform piles creating large rectangular assemblies, and containers turned, twisted, and stacked in organic ways that are anything but boring.

In short, containers don’t neatly fit into any narrow building category because they can be made to look like and do just about anything with enough work.

So, instead of trying to define container buildings by how big they are, how they look, or the type of people who might be attracted to them, we simply describe them only as what they are: structures built, at least in part, which shipping containers.

It’s a mistake (albeit a common one) to assume that a container building implies a very narrow view of just one of the possibilities we mentioned above. We’ve found over time that this myopic understanding of containers ends up confusing everyone from the general public, to building officials, to future neighbors and friends.

In a perfect world, if you say the term ‘shipping container building’, someone listening should think “well, that could be almost anything, so I’d better find out more details”.

It’s kind of like how saying ‘boat’ could realistically many anything from a rowboat to a massive luxury yacht. If you say you live in a shipping container house, you’ve only truly described the manner of construction. The description may reflect the size and architectural style, but it doesn’t necessarily have to.

In other words, deciding to build a shipping container home is not the same thing as deciding you want a small house or a house with a metal exterior. In many ways, these are mutually exclusive decisions.

We emphasize this point to ensure that people don’t prematurely rule out construction options based on false or incomplete ideas. We’re pushing to make ‘container home’ an intentionally broad term in order to leave room for innovators and people who push the limits of design in multiple directions!

In the next section, we will give you the main pros and cons of what you can expect from this type of build. We recommend you first give some thought to what it is you want out of a home in general and compare it to the factors below to see whether container housing is right for you.

Benefits

Container homes have a lot of great qualities, but they certainly aren’t for every person and every situation.  Let’s begin by talking about some of the specific qualities of shipping container that you may find advantageous. Further down, we’ll highlight some of the challenges you might face with containers.

Remember, some of these benefits might be more or less relevant to you. So compare your personal list of preferences to those below, and decide whether they influence your decision one way or the other. It is important to remain focused on the preferences that actually matter to you.

benefits-thumbsup

Affordable

While not always cheaper than more traditional types of construction, many people do find that building with containers does save them money. This can be caused by a combination of factors such as design choices, overall size, and amount of DIY labor.

Containers have certain advantages over traditional construction, and if you harness those in the right way, there can be economic benefits. The trick is to try to accept containers for what they are and work with them instead of against them.

To read more about the design and construction decisions that help make container buildings cost-effective, read The Honest Truth about Shipping Container Home Affordability. Perhaps more important than purely setting out to save money is to go into a build with realistic expectations.

Sustainable

When people think of being ‘green’, ‘eco-friendly’ or ‘sustainable’, one word usually pops in their minds: recycling.  But ‘Recycle’ is actually the last step in the hierarchy of waste management as expressed in the 3 R’s (Reduce, Reuse, Recycle).

Shipping container construction is a great example of ‘Reusing’ a material or product. It introduces a second useful lifecycle for used shipping containers that are no longer suitable for their intended purpose of carrying goods.

In addition, when coupled with the ideas of minimalism and tiny houses, containers can also address ‘Reduce’ through decreased usage of building materials and natural resources.

To learn more about the green side of container construction, read Supercharge Your Sustainability with Containers.

Strong

Given that they are made of steel and designed for long journeys across the open ocean, it’s no secret that containers are built to be extremely strong. Their ability to withstand wear and tear, handle extreme loads, and last for decades also means that cargo containers have related benefits when used for construction.

Whether you’re concerned about withstanding mother nature, keeping your family and possessions safe, or just building a home that will last for generations, a shipping container building offers some compelling advantages.

If you’d like to better understand how the toughness, stability, and longevity of containers will benefit you, read Container Homes are CRAZY Strong (And Why That Matters).

Unique

Empty shipping containers are intentionally made so that they are exactly the same size and shape as millions of others. So how are they unique? In the same way that every painting is just a canvas with some paint on it. What’s unique isn’t the material itself, it’s what you can do with it!

On the surface, it may seem ironic that a utilitarian item made to be uniform can result in incredibly unique houses and buildings. However, when you think about all the ways they can be modified, combined, and utilized, you realize how endless the possibilities really are.

For more information about the distinctive design possibilities of containers read Six Ways Containers Homes are Wonderfully Unique.

Flexible

Separate but related to the unique options of container design is their inherent flexibility. Thanks to the existing infrastructure that moves them by sea, road, and rail, containers have tremendous flexibility in how/where they are built, how they are moved, and even how they are used.

Want to have your container building fitted out in a factory, then shipped to your building site ready to assemble? You can do that. Would you rather work on your containers as a DIY project, spreading your construction over months or even years, while knowing that your building will be safe and secure through it all? You can do that too.

Many people give much more thought to where they want to place their container home than how they want to build it. Whether it is meant as a weekend getaway or a primary residence, many outdoorsy people love the appeal of a home they can set-up in nature relatively easily.

Due to their ease of transportation, shipping containers are fairly easy to set up almost anywhere. And if you’re interested in going off-grid, container home living offers a great way to achieve this lifestyle.

Container houses offer tons of possibilities and flexibility for before, during, and after construction. We highly recommend homeowners and other interested parties explore some of the interesting options this flexibility gives you by reading Eight Ways the Flexibility of Containers Will Blow Your Mind.

Challenges

It’s no secret that we’re big fans of shipping containers. However, we want to be as objective as possible and help you make good, well-informed decisions about using shipping containers.

There is a fair bit of bias in the online world of container homes and concerns about containers are sometimes glossed over.  We’re not here to trick anyone, and we want everyone to go into a decision this big with their eyes wide open.

In this section, we share several of the common objections about using containers for construction. We’ve done our best to be fair about these legitimate concerns.

However, we’ve specifically chosen the word ‘challenges’ in this section for a reason. While what we talk about below could easily be labeled as downsides, cons, or other negative words, we choose to frame them in a different light.

challenges-chess

Challenges are simply problems to be solved, while negative words like the ones we just shared imply a more fatalistic view in which nothing can be done.

Also, exactly how negative these factors are will certainly depend on your expectations and what you actually want out of a home. So go into this section with your own requirements in mind, and be honest with yourself about how much of a drawback these factors are to your own plans.

If the benefits we discussed above resonate with you, then most of the challenges below can be overcome. If you want to see how to do that, we discuss ways to mitigate many of these supposed negatives in the other sections of the Learn area of our site!

Room Widths

While shipping containers come in a variety of lengths and several heights, they basically only come in one width. With the exception of 53-foot containers available in the United States, virtually all shipping containers are 8 feet wide.

After taking into account the interior walls and insulation that are usually added, you end up with an interior room width just a bit over 7 feet. If you aren’t good at visualizing spaces or haven’t spent time inside a container building, you may have trouble understanding the importance of this measurement.

Trust us when we say that’s narrow. And if for some reason you don’t trust us, you can trust the 2018 version of the International Residential Code. Section 304 of the IRC calls for all habitable rooms (a space for living, sleeping, or eating but not kitchens, bathrooms, halls, or storage/utility spaces) to have a floor area of at least 70SF and a width and length of at least 7 ft.

What this means is that a shipping container would be in compliance with the code, but it’s close. Whether your particular area uses the 2018 IRC is kind of beside the point.

The thought here is that these standards are created to ensure the safety, health, and livability of occupants. While you aren’t in any danger, you may find yourself frustrated if you’re transitioning from a larger house with wider rooms, or if you have a big family.

Thankfully, it’s pretty straightforward to place shipping containers next to each other and cut out portions of the walls. This creates rooms that are 2x, 3x, or even 4x wider than normal, depending on how many containers you use.

You also have the option of enclosing the area between two parallel but separated containers, giving a wider space for living areas and focusing the space that’s actually inside the containers on things like bathrooms, storage, kitchens, etc.

To summarize, the problem of narrow rooms can certainly be overcome. However, it will require some slightly more complex construction skills and additional expenses. While very doable, we want you to be prepared for a few additional hurdles that can impact the project timeline and budget.

Insulation Location

Containers are interesting in that the corrugated metal ‘sheathing’ also serves as an integral part of the structure. This effectively means there is no cavity inside the walls in which to place insulation, unlike a typical wooden wall with studs.

Therefore, the insulation has to be placed on either the inside or outside of the corrugated metal sheathing. This is, of course, assuming you need insulation, which is true for most cases but not all.

Due to the fact that most insulating materials are generally somewhat unsightly and not very durable, you typically end up covering insulation in some way. If you put insulation on the interior side of the container, you’ll need an interior wall surface over the top of it to provide a better aesthetic appearance and give an easier place to mount cabinets, light switches, etc. Of course, you have to consider that this means even less available space inside the container.

If you put insulation on the exterior side of the container, you’ll need exterior cladding on top to better protect it from mother nature and provide a more visually appealing look. In addition, you might want interior walls anyway unless you’re ok with corrugated metal walls inside your home.

Neither of these options inherently ‘bad’, but they are important to consider as they represent some tradeoffs you may need to make when thinking about your design.

You can find more details about situations in which you would and wouldn’t need insulation, as well as discussions on the merits of interior vs exterior insulation in some of the other articles in the Learn area of the website.

Generally speaking, unless you live in a “perfect” climate, you are probably going to want insulation in your container home. The decision not only impacts personal comfort with regards to temperature but also internal relative humidity and utility bills.

Utility Spaces

Unless you’re living or working in an industrial building with surface-mounted conduit and exposed ducting, you’re probably used to having all of your mechanical, electrical, and plumbing systems hidden behind walls, ceilings, and floors.

For the most part, this is possible with containers as well. For instance, most electrical lines have a small diameter that is easily conceilable in a wall. The same is true for plumbing except for drain, waste, and vent (DWV) lines. DWV lines are thicker pipes, usually PVC, but they can often be run vertically where they penetrate the floor or ceiling and don’t require a thicker wall cross-section for the whole house.

Central air conditioning (and occasionally, heating) presents its own challenge that can be especially problematic for container buildings. The evaporator unit typically sits inside a traditional house in a ceiling or closet space with a spiderweb of air ducts reaching to all corners of the house. These ducts are often about a foot in diameter, and thus they can’t effectively be run inside of walls.

Instead, air ducts are usually run in ceiling cavities for homes with slab-on-grade foundations. In houses with crawl spaces or basements, the ducts are sometimes run underneath the house.

Even when using high-cube shipping containers, there really isn’t enough clearance to run ducting in the ceiling while maintaining enough roof for insulation, light fixtures, etc. The problem is only worsened when you use regular-height containers.

As it turns out, the issue of ducting is fairly easy to get around. Duct-less or split-unit HVAC systems have been growing in popularity, and outside of the United States, are actually the standard choice anyway. These units don’t require any ductwork at all, but simply have a wall-mounted evaporator/blower that is connected with a small refrigerant line to a condenser/compressor unit outside.

Larger buildings may require more than one unit, but this can actually save you money by allowing you to easily control the climate of just the rooms you’re using.

If for some reason you do want a central HVAC system, you could run the ducting underneath the container by using a foundation system that elevates the container off the ground. Or, you could build a secondary roof system (perhaps, to get larger roof overhangs or to provide more roof slope that will reduce snow collection) and run ducting between it and the corrugated metal roof of the container. Neither of these are popular options compared to the simplicity of the ductless units discussed above but are certainly possible if desired.

If heating is more of a concern than cooling in your area, you have options like in-room radiators or radiant flooring that can provide heating from a central boiler with only small water pipes instead of large air ducts.

Needless to say, there are a lot of available options for how you handle utilities inside your container, so this isn’t really a show-stopping problem for most builds.

Building Code Confusion

Shipping containers are confusing to some building officials. Even if you know the rules, they differ depending on where you are and if the container home was built on-site or off-site.

Arguably a bigger problem is code interpretation. At some point, determining if what you’re trying to do is in or out of compliance is determined by a human being.

Early adopters in any domain often struggle for regulations to catch up, and containers are no different.  But thankfully, containers have been growing in popularity for well over a decade. Most people have at least some familiarity with the idea and it’s almost unheard of for a container home to just be outright forbidden.

In order to comply with the rules in your area, like building codes, you may need to make some modifications to your initial design. But as thousands of people have already proven, you can almost always get one built.

In the future, as the International Code Council actively works to incorporate specific language about container construction into the model building codes, any ambiguity left in the process should start to subside.

It is understandably difficult to navigate the bureaucracy administering the rules and regulations associated with following the zoning and building guidelines for shipping container homes. A great place to start for locating things like permit information is your municipality. They will inform you about what you need to do to get a container home built legally, and also the steps you need to follow to be compliant with any other levels of government as well.

However, to save yourself some headaches, it’s often helpful to consult with a professional designer or building contractor in your area.

Locating Experienced Contractors

Most people, even DIYers, end up getting some help from outside contractors. It’s rare that someone has the time, skills, and equipment to do every single task with building a container home, though it certainly does happen.

As you think about the possibility of hiring contractors to help with certain tasks, you have to decide how what level of experience you want and how involved you want to be.

If you’re looking for a ‘set it and forget it’ option, with contractors that don’t need much supervision, it’s best to locate a contractor that has experience in working with container construction before.  It’s not that it’s difficult, it’s just different. Depending on where you live, finding someone with this experience may be difficult, which is why we’ve listed this as a potential challenge.

However, there are over 100 companies around the world that now specialize in shipping container construction, and many more that work more as subcontractors with a particular trade, but have worked with containers in the past.

Assuming you can’t find someone with experience nearby, all hope isn’t lost. It just requires you to be very specific with contractors about what you want and to check up often on progress to ensure that your ideas are being executed correctly.

Look for contractors who seem genuinely interested in your project.  People that are mentally invested in your container home will usually avoid cutting corners and do any research needed on their end to ensure they do things the right way.  Our “How to Build a Shipping Container Home” eBook can also be a big help in ensuring you don’t get taken advantage of by an inexperienced or dishonest contractor.

Controversial Appearance

It’s an unfortunate reality that some people don’t appreciate container homes as much as you might. A lot of this stems from a lack of information, although it’s becoming less and less of an issue with the increased media coverage of amazing container homes and buildings.

One of the great things about humans is that everyone can have individual preferences. We are all different and have our own likes and dislikes, which is a good thing. Otherwise, all of our homes would look exactly the same!

As we talked about at the beginning of this article, people occasionally have a very biased idea of what a container home will be. They may jump to conclusions, assume the worst, and create resistance. Perception can be reality and it’s something you might face.

We’re certainly doing our part here at Discover Containers to help educate and inspire people about all the creative ways containers can be utilized.

As a prospective owner and builder, depending on where you’re located, you may have to take a similar role. We often tell people that by building a container home, they are also signing up to be a container ambassador. It’s a role that’s usually fun and introduces you to many curious and friendly people who’ve only seen a picture of a container building and are excited to see one in person.

But, it may also require some less glamorous work on the front-end of your project, where you may need to help show some of the various stakeholders more about what you’re planning to build and how it will be an asset to the community.

Every new container building that’s constructed helps to eliminate these negative perceptions, and it’s quite possible you won’t face any problems like this at all. But if you do, most people are able to be persuaded when you can demonstrate that you’re building something nice that isn’t going to be an eyesore or negatively affect their property values.

Safety/Health Concerns

A common concern among prospective container home builders is safety and health. Whether it’s the possibility of pesticides in the floor, lead in the paint, or electrocution from lightning, people have serious concerns about their well-being if they choose to live in a container.

The truth is that almost all containers with a wooden floor do have pesticides applied to the wood. And while your chances of encountering lead-based paint are very low, the durable, industrial paint used in containers could contain some other chemicals.

However, it’s important to understand that the mere presence of chemicals isn’t necessarily dangerous in and of itself. It’s the exposure to chemicals at certain concentrations and over certain time periods that may be problematic.

The good news is that even if your container DOES have chemicals in the paint and flooring that are unsafe (and that’s usually more the exception than the rule), you have several abatement options. First is the removal of the floors and sandblasting of the paint. This is labor-intensive, expensive, and actually introduces new hazards as chemicals that were contained in these materials become airborne. Specialized personally protective equipment (PPE) is needed, and it’s often best to leave this to professionals. But, you will completely remove any questionable materials for good.

A simpler and easier way is encapsulation. By covering up the floor and walls, you keep any potential chemical off-gassing contained. As an added benefit, you make the container look much better and you were probably going to do it anyway.

As far as lightning goes, shipping container buildings really aren’t much different than the safe metal buildings that are found in almost every city and town in the world. They do require grounding to the earth, but that’s not anything especially unique to just containers. By reading and complying with the electrical code in your area or getting the help of a licensed electrician, you can ensure that a container has no additional risk to lightning.

Making The Right Choice For You

Through this article, we have presented you with basic facts about shipping containers and the container home industry. We then gave you a comprehensive guide to the potential pros and cons as they relate to your decision to pursue a container home build.

As our number one tip, we recommend you first decide what you are looking for out of a home. Think of your dream home, and think of what you want in terms of price, location, features, and more.

Then, read through this article with these factors in mind. It’s not about the pros and cons of shipping container homes in general, it’s about what these pros and cons mean to you.

Summary

We hope that through this article, you’ve found some new reasons to appreciate the world of shipping container building. We love them and hope that now, you do too!

For those who would like additional detail and examples for each of the benefits discussed, be sure to visit the articles listed at the end of each benefit section. These articles explain each particular benefit in-depth for those who really want to learn all they can.

And if you’d rather see a list of all the Fundamentals articles in one place, here they are:

How Are Shipping Containers Made?

We see shipping containers everywhere now. They’re being used as homes, swimming pools, cafes, and offices. With this, it’s very easy to forget where shipping containers came from and what