Are Container Homes Pre-Manufactured or Prefabricated?

While designing container homes for my clients, I have been asked if their container homes are considered to be pre-manufactured or prefabricated. What is the difference?

Pre-manufactured container homes are made in a factory on a movable chassis with wheels attached below them that can stay under the home after it arrives at the site.

Prefabricated container homes are partially or entirely made in the factory and they are placed on a foundation without wheels at the site.

There are reasons that people choose one method over the other because each way offers a different set of benefits. I usually advice my clients to build their container home as a prefabricated home. Here’s why:

Pros and Cons of Pre-Manufactured and Prefabricated Container Homes

Pre-manufactured container homes have to be built under different rules that prefabricated container homes are required to follow.

In the construction industry, these rules are called codes. Every state and some large cities have their own codes to be followed.

Pre-manufactured construction follows a different set of codes that is overseen by the Department of Housing.

Prefabrication construction in most cities of the US is now following variation of the same code called International Building Code or International Residential Code.

The local inspectors are very familiar with these codes and will need to inspect the construction of the prefabricated container home as a “rough inspection” before the interior walls are completed installed. Then, they will inspect the home after all construction is substantially completed.

If part or all of the prefabricated container home is built inside a factory, the “rough inspection” might occur in the factory. But, this can get a little complicated if the factory is in a different area that follows a different building code than where the container home will be delivered.

In the US, many cities have zoning laws and ordinances that require homes built in their communities to be permanent and not mobile. So, designing the home to be prefabricated – a home without permanent wheels – begins to be the better option.

If the container home is to be placed in an area that does not have restrictions of having wheels, then building as a pre-manufactured container homes has some advantages.

Having a mobile container home will allow the home owner to move with their home. They will need to find another community that allows for mobile homes to be placed. This could limit where the home owner can live in the future.

Pre-manufactured container homes will usually be constructed inside a factory that allows the construction workers to continue their work in any weather. Materials can be stored and construction can continue indoors even when it is snowing or raining outside.

Knowing that weather will not stop or slow down the construction schedule can help plan on earlier site installations. It can also help reduce the construction budget since the construction workers will not have idle time with multiple startup costs.

When pre-manufactured container homes are built in the factory, they will already have the doors and windows cut out of the exterior walls and installed before being delivered to the site. Oftentimes, these items are installed on the site if they are unaltered prefabricated shipping containers delivered to the site. This would mean that the contractor will need to add the lintels and beams necessary to support the opening cut out of the exterior walls of the shipping container at the site.

Whether the container home is pre-manufactured or prefabricated, the dimensions of the shipping container used in either construction method allows the home to fit on roads and under bridges, through tunnels, and to clear overhead signs. So, either type is a good option in terms of travel ease from the factory. 

But, there are still some big distinctions between pre-manufactured and prefabricated container homes as you will see below

Not All Parts of the Pre-Manufactured or Prefabricated Container House is Built in the Factory

Even though the pre-manufactured and parts or all of the prefabricated container house is built in the factory, there are still pieces of the home that will still need to be installed at the site.

If there are several modules that make up the entire container house, then all of these modules will need to be connected at the site. The joints along the sides, roof, and floor will need to be tight and weatherproof.

Plumbing fixtures, electric and natural gas appliances will usually be installed into the pre-manufactured container homes, and some pre-fabricated container homes, while in the factory. But, the plumbing and natural gas pipes along with the electric conduits will need to be connected to other modules and to the utility hook-ups at the site.

Cabinets, countertops, and lighting will also be installed in the factory prior to be delivered at the site for pre-manufactured container homes. But, for prefabricated container homes, it is common to have these delivered and installed at the site.

Exterior finishes are often delivered and installed at the site for both pre-manufactured and prefabricated container homes. It is often best to install exterior wall siding, brick, stone, and any other building material after it arrives at the site. Otherwise, these items could be damaged during delivery from a factory.

Factory Construction Can Be More Economical

The contractor can save a lot on material and labor by building the container home in the factory. This is especially true if there are several similar modules to be built. Then, the work can be systematically built in an assembly line fashion with more ease in the factory than at the project site.

Be sure to have the contractor share any saving with your project’s budget.

Advantages to Building Prefabricated Container Homes at the Site

Although it is not an option to build the pre-manufactured container home from scratch at the site, it is very common for prefabricated shipping containers to be delivered to the site. Then, all of the remaining construction is done at the site.

Local contractors can be held accountable to provide a quality home sometimes more than a factory worker many miles away. They have a reputation to uphold within the same community that you will be living.

Using a general contractor for the site construction of prefabricated home can help keep the project on time and on budget.

There are a lot of trades that the general contractor will need to coordinate. These trades would include subcontractors who clear the land, pour the concrete foundations, masons, steel workers, carpenters, roofers, door/window installers, interior finish providers, plumbers, HVAC contractors, and landscapers.

Be sure to choose a general contractor who will be attentive to the day to day construction process. That would mean the general contractor should be at the job site every day to direct their subcontractors, protect the construction site from theft and to insure that the quality of the craftsmanship is of the highest level.

Many of the good general contractors and their subcontractors are already familiar with the local inspectors and what those inspectors are particularly looking to inspect. Knowing this will also make the project run smoother.

Choice of Interior Finishes for Pre-Manufactured vs. Prefabricated Container Homes

If the container home is a pre-manufactured construction, the interior finishes are often chosen from a more limited set of choices. This limited choices make it easier for the factory to limit their expenses and maximize their profits.

If the container home is a prefabricated construction and built primarily at the job site, then an independent interior designer can select the finishes for an unlimited set of choices.

The countertops, cabinets, flooring, paint, light fixtures, appliances, window treatments, plumbing fixtures, bathroom accessories, moldings, and many other items can be custom selected with usually more ease than if factory built as a pre-manufactured container home.

Architects and interior designers can help design the prefabricated shipping container home with the end user’s lifestyle and preferences in mind. A home is a very personal place that deserves the attention to details that pre-manufactured homes do not often offer the end user.

In summary, first look to see if the local municipality where the container home is to be built requires the container house to be connected to the foundation or if they allow it to be on a movable chassis. This will probably direct whether the container house can be a pre-manufactured or a prefabricated construction.

Because the municipalities will require the container house to be permanently part of the site and the house can be designed and built with more attention to custom details, I usually recommend that container houses to be prefabricated instead of pre-manufactured.