Derek Sherrell, "That ADU Guy," is a Southern Oregon ADU developer with 28 years of experience in design, permitting, and construction. He offers custom permit-ready ADU plans, consulting, and free first-time buyer guidance.

That ADU Guy, Ashland, OR

About That ADU Guy

About Derek Sherrell – That ADU Guy

Derek Sherrell is a seasoned ADU developer and contractor based in Southern Oregon, with nearly three decades of hands-on experience in designing, permitting, and building accessory dwelling units. Growing up in the Cascade Mountain range, building was always a natural calling for Derek. A dedicated high school Wood Shop teacher first introduced him to the construction trade, which led to a carpenter apprenticeship and eventually a career as one of the youngest licensed building contractors in the region.

Over the years, Derek has built ADUs for clients, friends, and his own investment projects, developing a deep understanding of every facet of the process — from planning and permitting to financing and construction. His portfolio includes a range of project types such as detached living spaces, cottage clusters, barn cabins, loft conversions, and historic district builds, demonstrating a versatile approach to accessory dwelling unit development.

Derek's mission is rooted in a genuine passion for addressing the housing crisis, particularly the shortage of workforce housing and multi-generational family dwellings. He believes that the ADU strategy has become a necessity in many markets where home prices are cost-prohibitive, and he has dedicated his career to helping everyday people leverage this powerful housing tool to build passive income and greater financial independence.

Custom ADU Plans and Design Services

Derek and his team offer custom, permit-ready ADU house plans tailored to meet local standards and regulations. Their design service is built around accessibility and affordability, making it easier for homeowners to get started without unnecessary financial risk.

  1. Initial drafts provided within 10 business days
  2. Best pricing in the market with a focus on affordable design
  3. Low-risk payment structure — start with a retainer, then pay the balance only after plans are approved

This approach makes professional accessory dwelling unit design accessible to a wider range of homeowners, including first-time buyers exploring the ADU strategy for the first time. Derek also offers free ADU consulting for first-time home buyers, providing expert guidance at no cost to those just entering the market.

ADU Consulting and Open-Source Education

Beyond building and design, Derek is deeply committed to education and community knowledge-sharing. He offers personalized ADU consulting services that guide clients through the complexities of the process — from navigating red tape and zoning regulations to identifying financing options and avoiding costly mistakes. With 28 years of experience, his consultations cover every practical aspect of planning and executing a successful ADU project.

Derek has also developed a comprehensive, open-source video series that walks viewers through every step of the ADU journey — from selecting the right property to designing and financing a space-efficient home. Whether someone is looking to build a rental unit, a backyard cottage, a granny flat, or a guest house, the series is designed to make the process approachable, affordable, and sustainable.

His work is driven by a clear mission: to contribute to the ADU movement, teach people how to create passive income, and share knowledge with anyone ready to take the plunge into accessory dwelling unit development. Derek Sherrell — known widely as That ADU Guy — continues to be a trusted resource for homeowners, investors, and first-time buyers alike.

Services

That ADU Guy performs the following services

  • Architecture & Design
  • Permit Specialist
  • Construction
  • Financing & Loans
  • Feasibility & Site Assessment

That ADU Guy Reviews

Larry Paine

2025-10-10
"Derek provided great advice for me as a new ADU investor. He was super patient, answered all my questions, and set me on the right course for successful real estate investing. Thank you Derek!"

Erika Goering

2025-09-08
"Called Derek this morning. Picked up right away and shared eight minutes of his life and the most positive and helpful way. I was able to ask questions about the Two bedroom two bath home that he has provided the plans for. He cleared up a lot of questions and gave me great advice on what to do next. It is clear that he loves people and wants to improve the lives of others. His focus on community And affordable Housing is very encouraging and motivating. It has to be such a risk to put your number and email out there for everybody in the world to reach out to you. I appreciate How he makes himself available And is willing to help Everybody that he comes in contact with. Thank you, Derek, From the bottom of my heart. Brian"

Aron Choi

2025-02-23
"Consulting with Derek has more than paid off for itself in many hours saved, trusted contacts, a lot more clarity on next steps, and potentially avoiding tens if not hundreds of thousands of dollars in mistakes. Were are in the early stages of evaluating land to develop or finding existing homes with ADU potential. Derek is a great diagnostician that helped to understand our goals and values and helped us think through the pros and cons of next steps. After speaking with Derek, I realized how much more I didn't know even after doing a lot of my own research. Most importantly, our conversation helped my wife and I get on the same page and got us excited about getting our next property and building our first ADU. Thanks, Derek!"

Nancy Morgan

2024-12-23
"5 stars! I had been interested in finding out if I could convert my 1941, one-car garage to an ADU so I signed up for Dereks 15-minute consultation. The information and insights I received were priceless! I learned so much and am now weighing the pros and cons. And there are both. Dereks knowledge and expertise were invaluable. Above and beyond!"

Ryan Barnes

2023-12-27
"Derek and I are longtime friends, we meet in the Fire Service 12 years ago both residents in Southern Oregon. Derek has helped me with every project imaginable. His videos are priceless just recently with the ability to learn from his knowledge I managed a project at my home, completing a complete bathroom remodel. Although not an ADU, I saved 20k managing the project with Dereks help! Wanted to share a few pictures."

Specifics

Licensed Eco-Friendly

Opening hours

Monday 8:00AM - 5:00PM
Tuesday 8:00AM - 5:00PM
Wednesday 8:00AM - 5:00PM
Thursday 8:00AM - 5:00PM
Friday 8:00AM - 5:00PM
Saturday -
Sunday -

Location

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