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The True Cost To Build a Prefab House in 2021


Prefabricated structures come in all shapes, styles, and sizes you can imagine. From shipping container style modular homes to panelized material packages, and much more!

What can oftentimes be difficult to understand, is how much it will actually cost to build a prefab house of your own. Considering, the material package is just one of the many elements that must come together to complete the build. 

Variables such as the location of the property, the location of the structure on the property, and the overall degree of personal customization can have a sizable impact on the turnkey pricing which makes this topic rather difficult to generalize. 

You may have even heard us say that our structures typically cost 3 to 5 times the cost of the material package to be constructed. So, in an effort to help you better understand how the multitude of variables impacts the cost of each structure, we have created a short guide. 

First, touching on what prefab really is. Next, discussing the two most significant variables that impact the cost of a prefab home. Wrapping things up by discussing all of the other costs associated with the construction of a prefab home.

Let’s get started:

what is a Prefab Home?

“Prefab” in the context of residential construction refers to the prefabrication of all building materials in an off-site facility. The materials are then sent to the location of the project to be assembled on-site in a streamlined manner. Therefore, a prefab home is a home that has been constructed using prefabricated building materials.

For more information on prefab, check out our in-depth blog on the topic; “What is a Prefab Home?”.

The 2 Most Significant Variables That Impact the Cost of Prefab Homes


Location is probably the largest factor that influences the cost of building a prefabricated home. Simply put, depending on where your job site is located within the United States, the cost to construct a prefabricated material package is going to vary. 

As we get into the construction costs associated with building a prefab home, you will see how nearly every cost is associated with the location. Whether it be the location of the structure on the property or the location of the property with respect to suppliers, it all makes an impact. 

Degree of Customization

When you purchase a prefab material package with Trinity Building Systems, you have the ability to customize each and every element of the home. The models displayed on our site can be constructed as is, but they can also be used purely as a source of inspiration for your own custom designs. 

The starting price on our website represents the base cost of the materials for each one of our designs. That price can then go up or down depending on how you would like to customize your structure. 

For example, timber elements can be subbed out for traditional stick framing in certain situations to cut costs. While in other situations, floor plans be can expanded to include another bedroom or bathroom which would result in an increase in price. 

Therefore, customization of any structure will cause the material cost to fluctuate. What is most important, is that you approach the design stage of the project with an understanding of how each element is going to impact the cost. That way, you can design a structure that suits your needs while also staying budget-friendly. 

Get in touch with one of our project managers to get started on your project today!

So, what costs are required to construct a prefabricated material package?

When you purchase a prefabricated material package to construct a custom home of your own, you must take into account the numerous factors that impact the cost of the complete (turnkey) build.

Site Prep

Although it may not seem like much, job site preparation can be a very costly and time-consuming process. The composition of the land, the grade of the land, the location of the site on the property, the access to utilities, and the presence of existing structures can all impact the cost of preparation.

If you are building on a lot that has never been developed, the process typically will go as follows:

    • First, the land needs to be professionally inspected to gauge the rigor of the job and the resources needed to prepare the site. 
    • Next, the job site is cleared of all obstructions so that it can be leveled in order for the foundation to be set. 
    • After all of the obstructions have been cleared, heavy machinery is used to level the job site to the necessary grade for the project so that the foundation can be installed.

This entire process can range from just a few thousand dollars, up to tens of thousands of dollars depending on the size of the job site, the location of the site and ease of access, as well as the composition of the land (rocks, trees, geological formations, etc..).

Job site preparation on a lot with an existing structure can be a very pricey endeavor. Demolition requires specific permitting and experienced crews in order to be done properly. Typically the only place where you will save money on a demolition project is the development of a driveway and installation of utilities.


Prefabricated homes can be set on just about any style of foundation you can imagine, but depending on what you’re looking for, the prices may vary. 

Concrete slab foundations are the standard in a majority of residential and commercial construction. They are rather simple to install on a well-prepared job site and require a minimal amount of material in comparison to crawl space and basement style foundations. Therefore, a concrete slab foundation is the most economical foundation option available. 

A crawlspace foundation is a foundation that has been lifted a couple of feet off of the ground level of the site. The crawlspace style foundation allows for improved ventilation throughout the structure and provides easy access to utilities such as plumbing and electrical.

Crawlspace foundations require the use of more raw materials and can be more difficult to install depending on the grade of the site. Because of the increased ventilation, a crawlspace will oftentimes require increased insulation to ensure the structure is as energy-efficient as possible. For those few reasons in particular, the cost to install a crawlspace style foundation is typically greater than a standard concrete slab.

The third and final style of foundation you can incorporate into your prefab home is a basement foundation. Basements are the most costly style of foundation because they require considerably more materials, insulation, and labor to install.

A well-insulated basement can increase the property value, providing more livable and usable square footage to the property, but they do come with an increased cost. 

If you’d like to get in touch to discuss which type of foundation is most appropriate for your property and what it might cost in your location, reach out and one of our project managers will be in touch!


Freight is one cost that you just can’t escape when building a prefab home of any type or style. The materials have to be shipped from the source directly to the job site in ordered to be assembled in a timely and efficient manner. 

Depending on the location of the job site and the proximity to the suppliers of the materials, shipping costs are going to vary dramatically. 

For this reason, we like to discuss freight on a case by case basis. Each material package will consist of varying materials, varying weight, and many other factors that must be accounted for.

To give just a general idea, our freight costs may be as low as $5 per sq ft all the way up to $20 or greater per square foot. Resulting in a wide range that is very difficult to pinpoint until the design, and material package have been decided upon.

Material Package Assembly

Assembly of the material package once it arrives on the job site accounts for a lot of the construction costs. A skilled team is required to assemble the SIP paneling system,  timber frame components, and install the exterior finishes on the structure. 

Depending on the size of the structure, the degree of customization, and the location of the structure, the labor costs will fluctuate. 

When you work with Trinity Building Systems to construct one of our material packages, we want to ensure the structure is constructed properly the first time. That’s why we take the time to source the right contractors for our clients and their specific build. 

Sometimes, the right team for your project may need to be sourced from out of state and will require transportation and housing fees for the course of the project, On other projects, we may have an experienced team just around the corner who is able to keep costs a bit lower. 

No matter where you are or the type of structure you intend to build, we are happy to help source and vet the right builder for you.


Installation of utilities is one aspect of constructing a prefabricated home that may be overlooked. When we refer to utilities, what we are referring to is the freshwater system, sewage system, electrical wiring, and natural gas (or propane). 

Depending on whether or not the lot has utilities pre stubbed, the installation process can be a timely and costly endeavor. 

Beyond installation, the rerouting of utilities can be very costly as well. Re-routing is necessary when the stubbed utilities are located far away from the site of the structure on the property. 

The size/scale of the project and the geological composition of the property are the two largest factors in determining the cost. 

A rocky and tough to penetrate geological composition of the land makes the installation process very difficult. Often times large portions of rock have to be removed in order to route the utilities to the desired location on the property. 

The size/scale of the project refers to the location of the pre-existing utilities and the distance to the structure. This will impact the amount of material needed for the project as well as the amount of labor that is required to complete the job.

Interior Finishes

The interior finishes on a prefabricated home are typically left up to the general contractor of the project and the client. Meaning that all appliances, countertops, cabinetry, and decorative finishes are not included in the material package.

Therefore, the price for the prefabricated material package is purely for the exterior shell. When you begin to factor in the costs of your desired appliances, fixtures, and finishes, it is important to understand that price will be added on top of the package.

So, when you are designing your material package with a designer at Trinity Building Systems, keep your budget for the interior in mind considering the package is just the shell. 


Permitting is yet another variable that you have to factor into the cost of building a prefab home or commercial structure.

Just like every other variable that we have touched on, permitting costs are going to vary based on your state, city, county, or other local jurisdiction. Usually ranging from a few hundred to a few thousand dollars. 

The basic permitting covers construction permits, utility permits, as well as the construction of additional features or extensions. 

Depending on the local requirements, other permits may be necessary.


Unless you live in Montana, Delaware, Alaska, New Hampshire, or Oregon, you are probably pretty familiar with sales tax.

The prefabricated materials sourced for prefabricated homes and commercial structures are subject to sales tax. Therefore, you must factor into the cost of the package, the sales tax amount that will be added on to the top depending on the location the materials are sourced. 

Where sales tax gets complicated, is when you are sourcing materials from a state without sales tax into a state with sales tax. The materials are often taxed by the state with a required sales tax upon entry. 

Therefore, sales taxes will impact the final cost of your material package just about wherever you intend to build. That’s why it is important to understand how sales taxes will influence the cost of your project.

For more information on the sales tax in your local area, visit the “State and Local Sales Tax Rates, 2020” blog from

If you are confused or want more information on where the materials will be sourced for your specific project, get in touch with one of our project managers.

Interested in Building a Prefabricated Home of Your own?

Here at Trinity Building Systems, we understand that a lot of this information can be somewhat difficult to understand or truly comprehend. There are many moving parts involved in constructing a custom prefab home or commercial structure. 

In order to make this process as seamless as possible, we do our best to keep our projects under one roof. Helping streamline the entire process by sourcing the highest quality materials, skilled contractors, and most comprehensive financing options available. 

If you would like to get started on constructing the custom prefab home or your dreams today, give us a shout! Once we have a better idea of where you are located, the design you are interested in, and the specifications of the property, we can help construct an educated quote on what it will cost to bring that dream to reality.