If you are looking for ways to build an affordable DIY tiny house using free plans, you are not alone. As housing prices, rent, and costs of building materials are skyrocketing, the American dream of homeownership gets out of reach for many young people, new families, and retirees.
So, when our team came across the YouTube channel of Derek, That ADU Guy we loved the plethora of resources and ideas there. Not only is he on the mission to build affordable housing but he also believes in sharing his expertise. Furthermore, he provides free plans and 14-part video tutorials to teach people how to build their own cheap DIY tiny houses.

What is an ADU
Similarly, the official definition of ADU, according to the Americal Planning Association, states: “An accessory dwelling unit (ADU) is a smaller, independent residential dwelling unit located on the same lot as a stand-alone (i.e., detached) single-family home.” Surprisingly, ADUs go by many different names throughout the United States:
- guest house
- granny flat
- rental apartment
- in-laws’ suite
- apartment over garage
- pool house
- home office, etc.
As Derek explains, an ADU (or Accessory Dwelling Unit) should be a legally permitted secondary dwelling built on a lot that already has a primary house. So, this affordable housing solution is attractive because you already have the infrastructure to support the second dwelling: water, electricity, roads, sidewalks, etc.
Most importantly, Derek believes in his cause and lives in a 524 sq.ft. home that he and his crew built in Oregon for $60K in 90 days. Furthermore, you can explore what a 524-square-foot house feels like in a video tour of his DIY tiny home.
Furthermore, Derek’s mission in life is to build as well as teach people how to build affordable ‘in-fill’ housing in the markets where it is harder and harder to afford housing for working-class people. As his family could not afford a house when he was growing up, he was naturally drawn to construction at a young age.
Now, he has 28+ years of experience building housing, 300+ ADU builds, and has done 1000s of consultations for people interested in DIY tiny house construction. He is extremely generous with his time and his knowledge by providing free ADU plans and a 14-part series on how to build a DIY Tiny House.
ADU Laws & Facts
As an ADU revolution continues, more and more cities adopt legislation that allows cheap DIY tiny houses (ADUs) as secondary dwellings on existing residential lots. Now, many homeowners can use condo law or fee-simple law partitioning to make fractional ownership of land.
As a result, you can build more affordable housing for young singles and families who are not able to afford a house any other way. As local zoning laws and regulations are constantly changing, it is wise to check with authorities before starting your DIY tiny house ADU project.

Source: AccessoryDwellings.org
Free Plans for DIY Tiny House by ThatADUGuy
Interestingly, Derek Sherrell, ThatADUGuy, thinks that you must practice what you preach. So, to improve the design of the DIY tiny house he must live in it full time to have real-life experience.
Also, by doing so they were able to perfect the design of this 20’x24′ Barn Cabin and build it relatively cheap ($60K in Oregon) and quick (90 days).

As you approach the house, you are greeted by a 6-foot covered front porch. Furthermore, the porch cover protects the front door from the elements and gives you a space to enjoy morning coffee. Also, there is a pull-down ladder for attic access where you can store seasonal items and gear.
As you enter, you step into a great room with a 16-foot vaulted ceiling that makes the space feel bigger. Furthermore, you can open the double pocket doors that lead into the main floor bedroom (or office) so you can see all the way through. As a result, the space fills up with natural light and has more visual volume.
Next, as you step into the kitchen area, you find a spacious galley-style kitchen along one wall of this DIY tiny house. Equally important, this design allows you to save money as there are no turns and angles to cut for granite countertops and kitchen cabinetry.
Interestingly, as you continue touring this tiny house you realize that cutting costs comes from the simplicity of design but not compromising on the quality of materials. In reality, using granite, hardwood floors, and slate-stone tiles saves you money on maintenance costs in the long run.
Free Plans to Build DIY Tiny House/ADU

As you prepare to build your DIY Tiny House, explore all available resources and make a plan of action. There is a lot of thinking, planning, and learning you have to do before starting the actual building process:
- check your local zoning laws;
- decide on the design (contemporary, craftsman, minimalistic, farmhouse, etc);
- make a budget for your DIY tiny house;
- explore free tiny house plans;
- watch video tutorials on How To Build an ADU/Tiny House;
- download and finalize your Shopping List for appliances, light fixtures, etc.
Here are the 3 FREE SETS of FREE PLANS available, courtesy of ThatADUGuy Derek Sherrell:
- The Barn Cabin – 528 sqft, 1 bedroom, 1 bath
- 616 sqft, 1 bedroom, 1 bath
- 800 sqft, 2 bedrooms, 2 bath
It’s important to examine your day-to-day routine to figure out what floor plan fits your needs. With this in mind, download free plans, study them, and make a decision.
Keep in mind that while free plans can be a great starting point, you may need to make some modifications to customize the design to fit your unique requirements. By choosing plans that resonate with you, you’ll set yourself up for a successful and rewarding building experience.

Preparing Site for DIY Tiny House/ADU
Before you can start building your affordable ADU house, it’s essential to prepare the construction site properly. This involves clearing the area of debris, ensuring the ground is level, and having all necessary tools and equipment ready to go.
Firstly, make sure to watch the 14-part series, where Derek explains and shows every step of the process. Second, make sure to ask questions, as he even provides his phone number for consultations.
By taking the time to set up your construction site efficiently, you’ll be able to streamline the building process and minimize any potential setbacks. Once you have everything in order, you’ll be ready to move on to the next exciting step of constructing your ADU house.
In Summary
In conclusion, building an affordable ADU house using free plans is not only achievable but also rewarding. By carefully selecting the right plans, gathering affordable materials, preparing the construction site, and following budget-friendly tips, you can create a space that meets your needs without breaking the bank.
Begin your DIY project today and experience the satisfaction of building your own home. Remember, with a little creativity and resourcefulness, anything is possible. As the saying goes, “Home is where the heart is,” so why not put your heart into creating a space that truly reflects who you are? Start building your dream DIY tiny house/ADU and watch your vision come to life.