So, you've made the smart choice and have decided to construct a metal building. Now there's another decision to make: buy a pre-engineered metal building system or make over a shipping container.
Pre-Engineered steel buildings vs. shipping containers
Quick and affordable design
Typically, your PEB will have a quicker and affordable design and build process. In most cases, all of your engineering, architectural design and relevant sketches, drawings, and plans are included in the price of your metal building.
Metal building manufacturers have highly-specialized computer software programs and in-house designers and engineers who can quickly and efficiently tailor your building's design to your needs.
A shipping container…well, it's a shipping container. You get a 40-foot long metal box. However, it is a very inexpensive metal box, and it's already put together. You just need to cut holes for doors, windows, and any other openings you may require.
If you want fast and cheap, the shipping container is likely to win, but you do not get much choice in design.
Once you've decided on a building design, a metal building can arrive at the jobsite location in about six to eight weeks. A shipping container can be delivered shortly after you purchase it unless you are having it modified off-site. Once it arrives, you still need to get the utilities hooked in and a completed foundation ready to receive it.
Delivery speed may be a toss-up.
Quality control and building permits
Your steel building will be designed and fabricated in-house, with strict levels of quality control at every stage of the game. There is also the added advantage of a single source of safety and responsibility. It’s easy to build to code as well.
Shipping containers are purchased as is. Depending on the local codes, you may spend more than you think getting a permit for this type of structure.
A couple of other things you need to know about shipping containers. Some come with wood flooring materials that contain arsenic and the coatings that make them corrosion free on the ocean tend to be toxic.
A pre-engineered building is more likely to pass inspection and be erected with no quality or toxicity issues.
Smarter and more efficient design and build process
PEB frames are highly-specific to the project, without a pound of material wasted. They are typically constructed from standard steel plates stocked en masse by the manufacturer. The frames are usually tapered and have flanges and webs of variable thicknesses and depth along the individual members. The frame's geometry is more indicative of the internal stress of the building, reducing the number of materials used.
A shipping container is already a rather mass-produced product. However, you will require a contractor who is experienced in converting one to a living or commercial space. There are very few contractors available who are competent to reconstruct a shipping container. Labor costs may be higher, and you will need to wait on availability.
A prefabricated metal building that has already been engineered is easier to put together, and you will find more contractors with the right skill set.
Lighter overall building weight
Continuing with the idea of a smarter and more efficient design and build process, the precise materials used to construct a PEB result in a building that is 30% lighter than a conventional wood or stone structure. There is a tremendous difference in material costs, as well as the impact on the foundation and soils below.
A shipping container is similarly light-weight. It is also rather short on space both horizontally and vertically. Still, it doesn’t weigh as much as a wood-frame tiny house.
A lighter building requires a lighter foundation; a heavier building requires a heavier foundation. For that reason, your PEB will also mean a simpler and more basic foundation pour.
The same is true for a shipping container. Another toss-up.
The more flexibly a building can move during a seismic event, the less damage it typically incurs. The lighter and more flexible qualities of the materials used in a PEB result in a higher resistance to seismic tremors.
Shipping containers aren’t designed to withstand seismic events. There is not much in the way of a frame structure. There are unlikely to be studies on how shipping containers behave under seismic movement, so there is a question whether it would be a good choice to live or work in if your region shakes, rattles, and rolls frequently.
Better integration = better overall performance
When you order a metal building, the entire design process and all of the parts are tested and proved to work together as a functioning system. They have the same connections, so erection is streamlined and there is only one point of contact so, in the rare event there is an issue, the supplier will take responsibility and address it.
Shipping containers were never built to be used as buildings, and they certainly are not designed to integrate with each other outside of stacking easily. The premanufactured building wins this one.
It's always advised that you select a building design likely to accommodate your needs in 10 years as it does today. Even so, your facility may need to be expanded in the future. This is very easy to do with steel buildings since they're built with future expansion in mind.
Aside from integration issues, you can put more than one shipping container together. However, it would quickly become unstable without some additional bracing. You will need to create more doorways or openings if you hope to go from one area to another without going outside.
The prefabricated building wins this one too.
Steel is highly recyclable, and most steel is made largely of recycled steel. It doesn't lose any strength, there is no scrap going to the landfill, and less steel needs to be manufactured. So far, this counts for both the pre-engineered metal building system and the shipping container.
There are over 17 million shipping containers around the globe; only about 6 million are in use. The rest are just sitting around taking up space when they could be used for homes.
Either way, the Earth wins this one.
Prefabricated Metal buildings win but shipping containers may be okay
The advantages of a pre-engineered metal building mean you get to enjoy a higher-quality product, quickly, and at a lower price than conventional materials.
Shipping containers are certainly inexpensive to purchase, and you can take delivery quickly. You will be limited in your ability to expand and customize the resulting facility easily. The primary advantage is one of price if you do not care how it looks. There is no question that a shipping container is perfect for storage purposes.
A house or store made out of a shipping container is an interesting idea and, under certain circumstances, may be a good choice. But once you experience the advantages of a pre-engineered metal building firsthand, you'll never look back.