Are you tired of squeezing your home office into a bedroom, kitchen, or inappropriate room?

A prefab ADU is an exciting and innovative option for anyone looking to add living space to their home or even some extra storage space.

An accessory dwelling unit, or ADU, is a separate building on the same lot as the main house; it can be prefabricated and have all the same conveniences.

Prefab ADUs, in contrast to other options like a tiny house or a guest house, are simple to install in a backyard setting and don’t break the bank.

With this guide, I’ll cover all aspects of what it takes to get started with a prefab ADU, such as:

  • How much does an ADU cost
  • Different ADU designs and ADU models
  • Companies that offer turn-key ADUs with installation
  • Financing options available for one of these modular homes
  • The pros and cons compared to traditional construction methods

Let’s take the plunge into learning all there is to know about prefab ADUs below!

Why Consider a Prefab ADU?

A prefab ADU (Accessory Dwelling Unit) is a small, self-contained living space that can be built on an existing property.

Instead of using your living room as a makeshift office, you can setup an office in the backyard. 

Prefab accessory dwelling units (ADUs) are built in a factory and shipped to the construction site, where a professional assembles the modules.

Although prefabricated houses have been around since the 1950s, their popularity has grown in recent years due to the fact that they are more affordable and can be built more rapidly than conventional homes.

They offer greater design freedom by letting homeowners choose their own materials, colors, finishes, etc., to create one-of-a-kind sanctuaries that are ideally suited to their personalities and lifestyles.

Adding a prefab accessory dwelling unit to your property can save you money and reduce your carbon footprint.

Knowing how much a prefab ADU will cost you is important because there are many different kinds, prices, and ways to save money on a project like this.


Prefab ADUs provide a cost-effective and quick construction solution for additional space in your backyard, ideal for WFH. Benefits include:

  • Quicker construction time
  • More flexibility when it comes to design options
  • Cost savings over traditional building methods
  • Peace of mind and increased productivity with a dedicated work area

How Much Does a Prefab ADU Cost?

Depending on the features you want, the size you need, and the retailer you buy from, the price of having a prefab ADU installed in your backyard can range widely.

Autonomous, for example, has a few pre-built selections that start at $19.000 USD.

This is a cheap ADU compared to building a separate tiny home that can go up to $100k easily and take months to plan out and build.

prefab adu cost example

I did some serious digging and found that, on average, you can expect to pay as follows by the square foot:

  • ~100SF: $17-23k (Studio ADU)
  • ~400 SF: $200-300k (1 bedroom ADU)
  • ~600-1000 SF: $300-$400k (2 bedroom ADU)

But you should always get an accurate estimate for your specific project first, so it’s best to consult directly with the company that sells ADUs.

Factors that Affect Cost

The type of prefab ADU and home models you choose will have a big impact on the overall cost.

Prefab homes come in many styles and sizes, ranging from small studio apartments to larger units.

prefab adu alternatives

Location (and thus the cost of labor in that area), building materials, design complexity, interior finishes, extra features like decks or porches, permits required by local authorities, etc. all play a role in determining final costs.

Since they are easier to design and build, smaller prefab ADUs are typically less expensive than larger ones.

As mentioned above, a basic one-room studio apartment may start at around $20K.

Financing an ADU

When it comes to funding an ADU, a few options are available.

Loans and grants can be used to cover the cost of construction and any associated fees.

Tax credits and incentives may also be available in certain areas.

Additionally, other financial considerations should be taken into account when planning your project.

Loans and Grants Available for Building an ADU

Several loan programs are available for those looking to finance their ADU project.

These include FHA loans, VA loans, USDA loans, conventional mortgages, home equity lines of credit (HELOCs), and more.

In addition to these loan options, some states offer grant programs designed explicitly for building accessory dwelling units (ADUs).

Depending on where you live, you may qualify for tax credits or other incentives when you construct an ADU on your property.

Many cities across the country have passed ordinances allowing homeowners to build additional units without having to go through the usual permitting process.

It is important to consider all aspects of financing before beginning construction on your project, not just upfront costs such as materials and labor but also what you’ll use inside of your ADU.

Interior Desk Setup Ideas

If you’re building a real home studio for your online business and content creation needs, you’ll want to consider your desk setup with things like:

  • A standing desk
  • An ergonomic chair
  • A high-quality monitor
  • And lighting accessories

Now that you know about loans, grants, tax credits, and other financial considerations for building an ADU, let’s explore prefabricated homes from different companies and discuss their pros and cons.


Financing an ADU requires research and planning. Options include loans, grants, tax credits, incentives, and more.

Consider all costs upfront and ongoing, as well as potential furnishing, when making your decision.

Best Prefab ADU Companies

Many companies specialize in prefab ADUs, so it’s important to research before choosing one.

Many well-known companies manufacture or build prefabricated homes, but the prices can get out of hand easily.

Companies that specifically manufacture ADUs have years of experience building high-quality homes that meet local building codes, and regulations, and come with a multi-year warranty.

They also provide design services to help you customize your home to fit your needs and budget.



Autonomous is a work-from-home company that has expanded into the ADU space and delivers prefabricated ADUs across most US states, such as:

  • Los Angeles
  • San Francisco Bay Area
  • San Jose
  • Seattle
  • Southern California

Unfortunately, they don’t deliver to Hawaii or Alaska.

The ADUs are cheap and affordable, starting at only $17.000 USD.



Villahome specializes in ADU and the smallest unit is the M375 with a square feet of 384 for studio living starting at $105k.



Spacial delivers turn-key ADUs starting at 400 square feet with a price starting at $140.000 USD. Spacial delivers mostly for California.



Abodu has some beautiful backyard ADUs with delivery within 6 months and a seamless experience. Pricing is more premium and starts at $228k.



Classed as “micro-living”, Connecthomes offers amazing ADUs with square feet 460 and a price starting at $230k.



Fast and reliable manufacturing of prefabricated homes, with their smallest ADU at 625 square feet at a price of $480k.

Getting Started with Your Prefab ADU Project

Before you can begin building your prefab ADU, there are a few steps you should take.

Research local regulations and obtain any necessary permits or approvals from your city or county.

This will help ensure that your project is compliant with all applicable laws and regulations.

Also, consider what type of foundation you want for your ADU and how much work needs to be done on-site before installation begins, such as:

  • Concrete slab
  • Crawl space
  • Basement, etc

If possible, try to find a company that offers delivery and installation services so that everything arrives at once and can be put together quickly without having to wait for individual components over time.

Don’t forget to think about how long it will take for the construction of the unit itself, as well as any additional site preparation work, such as grading or landscaping, that may need to be done beforehand.

To make the process easier and faster overall, look into companies who offer turnkey solutions where they handle everything from permitting through completion of construction, including inspections along the way if needed by local authorities.

Some manufacturers provide detailed instructions with their kits, which can help streamline assembly times significantly depending on how complex they design each component.


When building a prefab ADU, research local regulations and permits, consider the foundation type and installation services needed, factor in extra costs for site preparation work, and look into turnkey solutions to make the process easier.

FAQs in Relation to Prefab Adu

What are the disadvantages of an ADU?

ADUs (Accessory Dwelling Units) can be a great way to increase the value of your property, but there are some drawbacks.

One potential disadvantage is that they may not be allowed in certain areas due to zoning regulations.

ADUs can require additional maintenance and upkeep costs which could be expensive depending on the size and complexity of the unit.

Lastly, if you plan to rent out an ADU it can also come with extra legal responsibilities such as tenant screening and landlord-tenant laws.

It’s important to research local laws before investing in an ADU to understand the associated risks and rewards.

Is an ADU worth the investment?

The answer to this question depends on the individual’s goals and needs.

An ADU can be a great investment for those looking for a separate workspace from the home environment.

Content marketers and small business owners may find value in having an ADU as it increases efficiency and productivity.

What qualifies as an ADU in California?

An Accessory Dwelling Unit (ADU) is a secondary dwelling unit that can be added to an existing single-family home in California.

It must meet specific criteria, such as being located on the same lot as the primary residence and having its own kitchen, bathroom, living area, and entrance.

The ADU must also comply with local zoning regulations regarding size limits and other requirements.

ADUs provide additional housing options for homeowners while preserving neighborhood character and increasing density in urban areas.

Wrap Up

Prefab ADUs are a great way to get started on your work-from-home journey.

With the right financing, prefab ADU companies, and knowledge of how much they cost and what to expect, you can decide whether this is the right move for you.

Whether you’re looking for extra space or want to start making money from home, a prefab ADU could be the perfect solution.