Modular Home Foundations — 2 Main Types to Consider

Part of what makes modular homes so appealing to many people is their flexibility. Unlike other types of home construction, a modular home is easy to customize without driving up costs. You can make the most of this potential to design the home of your dreams, starting with the foundation.

Modular homes offer two main kinds of foundations: crawlspaces and basements. In this modular home blog, we’ll explain everything you need to know about modular home foundations, the benefits and drawbacks of different types, and how to choose the best one for your new house. 

Why Foundations Matter for Your Modular Home

Century Home Modular Home with blue sky and green grass.

Modular homes are built off-site and transported to their final location on your lot. However, there’s one element of a modular home that can’t be made at a factory: the foundation. 

Modular home foundations are built on-site out of necessity. Whether you want a basement or a crawl space, the builder needs to work with the land to put it together. For instance, basements obviously have to be dug into the ground of your lot. Similarly, a crawlspace needs to be built on the land itself to take into account things like slopes and shifting soil. 

Your foundation is also important because it will support the rest of your home. When the individual sections of your house are delivered to your property, they will be placed directly on the foundation. Choosing the right style can significantly affect your home’s stability, energy efficiency, and livability. 

2 Main Types of Modular Home Foundations

The first choice you need to make for your new home is whether it should have a crawlspace or a basement for its foundation. Here in the Midwest, the two most popular modular home foundations are conditioned crawl spaces and poured-wall basements. Let’s break down these types to understand what they mean for your home. 

1. Crawl Spaces

A crawl space is an open area under the home that provides access to electrical and plumbing. The name comes from the fact that these spaces usually have to be accessed by crawling since the area isn’t tall enough for someone to stand upright. 

In the Midwest, crawl spaces are often the most cost-effective foundation type. A conditioned crawl space is best for your home’s construction costs as well as long-term energy efficiency. 

A crawl space doesn’t require you to dig as deep into the ground as a basement would. During construction, the foundation is built on top of the leveled ground. As a result, it’s faster and less costly. Furthermore, without a basement to heat and cool, these foundations also save you money in the long term. Your utility bills will be significantly lower as long as you live in your new home. 

On the other hand, a crawlspace doesn’t offer you any additional livable space the way a basement might.

2. Basement Foundations

Basements are created by digging down into the earth, building a foundation structure, then pouring concrete over it. The home is built on top of the basement. 

The largest benefit of a basement foundation is that it offers you more space. Depending on the size of the basement, you could as much as double your livable space. Furthermore, basements in the Midwest can also act as a tornado shelter.

Poured wall basements are best for modular home basement foundations. This construction method offers extra strength during the backfill process around the basement walls. When it’s time to transport in the rest of the home, this strength reinforces the ground on which cranes will rest as they lift the sections of your modular home onto the foundation.

The downsides of basement foundations are twofold. First, compared to crawl spaces, they take more time and money to create. Second, they lead to higher utility bills as you heat and cool your additional space.

Modular Home Foundations- Basement vs. crawlspace

2 Alternatives to Standard Modular Home Foundations

There are two other foundation types you might consider for your modular home: slab foundations and pier and beam foundations. These types are less common due to some fundamental drawbacks for Midwest homes.

1. Slab Foundations

A slab foundation consists of poured concrete slabs attached using steel reinforcement rods. The slab is placed directly on the ground, and the home is built on top of it. Unlike crawl space foundations, there is no gap between the floor of the house and the land itself. 

This is the biggest drawback of slab foundations. They prevent the construction team or the homeowner from having easy access to mechanical components of the house. 

Down the road, if items like plumbing or electrical conduits need to be repaired, a slab foundation makes the process significantly more complicated. That’s why slab foundations are not preferred for modern home construction.

2. Pier and Beam Foundations

The other alternative is pier and beam. A concrete footing is buried deep in the ground. On top of that footing, “piers” or concrete platforms are built. Finally, these piers support beams that hold up the rest of the home. 

Pier and beam foundations are designed to protect homes in places with frequent flooding. Most places in the Midwest don’t require this much protection. Unless you’re building your home on a known floodplain, you don’t need to go through the significant work involved in this style of foundation.

What's the Difference Between Conditioned and Non-Conditioned Foundations?

We used the term “conditioned” to describe certain crawl space foundations earlier. What does that mean? A foundation is conditioned if its walls and flooring act as part of the insulation for the rest of the house. Meanwhile, a non-conditioned foundation has no insulation at all. 

All kinds of modular home foundations can be either conditioned or non-conditioned, depending on how they’re built. Regardless of the type of foundation you choose for your home, it’s essential to make sure that you make sure it’s conditioned. The conditioning is vital for reducing maintenance costs on your home over the long term.

Modular homes are built so tight that reducing moisture buildup is just as important as supporting energy efficiency. A conditioned foundation effectively reduces your energy costs and prevents moisture buildup in your home. The conditioning keeps cool air inside during the summer and outside in the winter. It also keeps ground moisture from seeping into your house from the bottom up. Over time, that will keep your utility bills low and your home in better condition. 

The best conditioned foundation for energy efficiency and moisture protection is the conditioned crawl space. However, even a conditioned basement is better than one without insulation. Without the conditioning, you’ll waste money heating or cooling the ground. You can also develop moisture-related problems such as water damage and mildew.

What Kind of Foundation Is Best For Your Home?

Century Homes Modular Home

Once it’s time to choose your foundation, modular home information alone isn’t enough for you to make this decision. You also need to consider your local laws and conditions. Both crawl spaces and basement foundations have their benefits. The right one for your home will depend on things like:

  • Local building codes: In some municipalities, the building code requires modular home foundations to be built in specific ways. For example, towns in Tornado Alley often require new construction to include a basement no matter what to protect people from the weather. If this is true of your area, you’ll have to follow the building code’s requirements above all else. The code may contain specific requirements for the conditioning of your basement as well.
  • Climate: When building codes don’t make decisions for you, your environment might instead. If your area is prone to heavy rain or the water table is high, a basement may not be practical. Choosing a crawl space foundation in these areas can help you avoid problems like water damage.
  • Budget: You’ll also have to consider your budget when choosing a foundation. Basements take more work and therefore cost more than a crawl space. If you’re hoping to construct your modular home cost-effectively, opting for a crawl space is a better choice.
  • Personal preferences: Finally, your own preferences are fundamental. After all, this is your home you’re designing. If everything else is equal, you get to choose whether you want the extra space offered by a basement or the reduced costs of a crawl space.

Once you understand your local requirements, you can make an informed decision on the style of basement you prefer.

Your Home's Foundation Is Fundamental

While modular home foundations aren’t the most exciting part of the home design process, they’re essential to the long-term livability of your house. Depending on your local environment and laws, you have several options for your foundation. Conditioned crawl spaces and poured-wall basements are the best solutions for modular homes, but the choice is up to you. 

No matter what foundation style you choose, Century Home Builders will support you. You can learn more about how Century Home Builders can help you choose the right foundation for your modular home by getting in touch today. 

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