ADU Frequently Asked Questions

Prefab Home vs Modular Home, What is The Difference?


When in the market for an ADU or Tiny House there are many options and variations to choose from. Let’s walk though these differences to clarify what type you may need for your property. You probably noticed the varying terminology used so, let’s dive in.

Navigating the terminology isn’t easy. Since there are so few sources of up-to-date information about the latest trends in prefab homes, many clients come to us with questions on how to start and the permitting process within your area.

So what’s the difference between a prefab home, a modular home, a manufactured home, and a systems-built home?


What is a Prefabricated Home?

Prefabricated is a general term that doesn’t just apply to homes or buildings. The basic idea of prefabrication is simple: You pre-build important structural elements, move them to a building site, and then assemble them. This is not a new concept – In fact, building in this way has been around for thousands of years.

Prefabricated homes hit the mainstream in the United States in the first half of the 20th century.
Between 1908 and 1940, Sears, Roebuck and Co. – the very same Sears that announced its closure this month – sold more than 70,000 prefabricated homes. The homes were shipped via railroad boxcar and came in dozens of different layouts. They even had groundbreaking amenities like indoor plumbing!

Prefab today utilizes the same fundamental methodologies as those early homes described. The difference now is that you can buy prefabs of all shapes and sizes, and the technology has evolved to support a more savvy home buyer with high expectations for the way their home integrates into their world.


What is a Modular Home?

A modular home is similar to a manufactured home. Construction methods and most of the applicable standards are comparable. Instead of having an axle underneath it, however, it is shipped on a flatbed truck. This allows for a slightly greater variation in sizes.

The biggest difference in modular homes isn’t how they’re made, but how they’re regulated.
While regulations pertaining to manufactured homes are crafted at the federal level, each state has its own standards for modular homes. Standards may be lax in some states, so it’s even more vital to select a vendor with a reputation for excellence.


What is a Manufactured Home?

A manufactured home is a type of prefab structure designed to minimize cost and waste. It consists of a steel frame on which the portions of a house can be built. Underneath the structure is an axle so wheels can be placed directly on the home for transportation.

Today’s manufactured housing is used in many different ways, such as providing temporary housing to those displaced in the wake of natural disasters. You might also see it in mobile home parks: A mobile home or trailer is what most people picture when they think of a prefab home.

There are some severe drawbacks to a typical manufactured home:

  • Standards for manufactured homes are set by the federal government, not by state or local jurisdictions. Companies that make them submit to quality control protocols, but there are no in-person inspections – and no way to catch manufacturing defects before they cause problems.
  • Since sizes are so restrictive, there’s no way a manufactured home can take full advantage of the plot of land where it is situated. Preconfigured home models and sizes cannot be calibrated to the maximum allowable square footage of the lot, leading to a waste of land space.
  • The size of a manufactured home is limited to the size of the trucks used or the size of the load that highways between the factory and final site can bear. There are no wide or tall spaces within the home, and the final product can look quite a bit like a shipping container.

Prefab Systems-Built Home: The Evolution of Prefab homes.

Homes have evolved from manufactured to modular – and systems-built is the next step.

A systems-built home maximizes quality, construction speed, and longevity while reducing cost. By using sophisticated components that can be configured according to virtually any floor plan desired by the homeowner, a systems-built home has more opportunities for customization than any other type of home mentioned here today.

What Makes a Home Prefab System-Built?
Components of a systems-built home are produced at a factory. Picture walls, framing, windows, doors etc. These are then transported and assembled at the final site. The easiest way to picture it is if you imagine a life-sized set of Lego blocks! The blocks (components) can be arranged in various combinations to produce an infinite set of outcomes, while still using the same blocks.
What Are the Advantages of a System-Built Home?

For homeowners who want a long-lasting investment, the biggest advantage of the systems-built approach is that construction times are quick and quality is assured.

Home inspections take place based on the rules set by the local jurisdiction, and so your home will have to pass the same rigorous tests as any home built using regular construction methods, which is quite different from the other categories of homes mentioned in this article.
This can make it much easier to get financing for a systems-built home.
Why? Lenders know that systems-built homes can stand the test of time: With appropriate maintenance, they may last for centuries. Plus, overall ownership cost of a systems-built home tends to be lower than a conventional home’s, making it easier for homeowners to maintain their financial health.

Some system-built home builders, like us here at Prefab Turnkey ADU, have our houses categorized as “custom prefab homes” which puts them in the same bracket as any custom home; This makes everything from financing to inspection to zoning and more much easier to deal with because the home is more “typical” in the eyes of the city. This equals less red tape and less hassle for you.

The system-built home industry remains in its infancy, but it won’t for long. That industry is growing and changing by the day. New capabilities are unfolding even as you read this: Before you know it, AI could make it possible to design your new home from your couch…stay tuned for more on that!

Our Most Popular ADU Floor Plan for 2021

3 Bedroom | 2 Bath

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Standard Model ADU Floor Plans

Azalea ADU 360 SF

1 Bedroom | 1 Bath

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Poppy 600 SF ADU Model

1 Bedroom | 1 Bath

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3 Bedroom | 2 Bath

Vertical Build starting from

3 Bedroom | 2 Bath

Vertical Build starting from

2 Bedroom | 1 Bath

Vertical Build starting from