West Coast ADU is a California-based ADU builder offering prefab & manufactured accessory dwelling units. They help homeowners add rental income, house family members & boost property value with streamlined permitting & construction.

West Coast ADU, Santa Rosa, CA

About West Coast ADU

About West Coast ADU

West Coast ADU is a dedicated ADU builder and accessory dwelling unit builder based in California. Their story began in the aftermath of the 2015 Northern California fires, when they were among the first to step in and support families who had lost their homes. That commitment to providing immediate, quality housing solutions became the foundation of their mission — to serve their communities with integrity and purpose.

Today, with California's more lenient ADU laws, West Coast ADU focuses on delivering high-quality homes for low-income families, in-laws, adult children, and caretakers. By utilizing prefabricated and manufactured construction methods, they are able to streamline both the permitting and building process, offering a faster and more cost-effective alternative to traditional home construction.

The Benefits of Building an ADU

There are many compelling reasons why homeowners choose to work with an ADU contractor like West Coast ADU. Here are some of the key advantages:

  1. Affordable Housing: ADUs provide a cost-effective living option in high-cost areas, making them a practical solution for cities facing housing shortages and rising rent prices.
  2. Additional Rental Income: Homeowners can generate passive income by renting out their ADU for long-term tenants or short-term vacation stays, helping to offset mortgage payments and other expenses.
  3. Extra Housing for Family: As a trusted in-law suite builder, West Coast ADU helps families create independent living spaces for aging parents or adult children, enabling multigenerational living while preserving privacy.
  4. Increased Property Value: Adding an ADU boosts a property's market value and appeal, making it more attractive to future buyers.
  5. Flexible Living Space: ADUs can serve a variety of purposes — from a home office and guest house to a hobby studio — adapting to the homeowner's changing needs over time.

Their Simple, Streamlined Process

West Coast ADU has developed a straightforward process to make building an accessory dwelling unit as easy as possible for homeowners:

  1. Consultation & Site Inspection: They offer free estimates and assess the property to determine the best approach.
  2. ADU Design Selection: Clients can choose from hundreds of floor plans and sizes to find the right fit for their needs.
  3. Permitting Process: Through trusted partners, they help navigate the permitting requirements efficiently.
  4. Site Preparation & Construction: Their team handles all aspects of construction, delivering high-quality results on time.

As an experienced detached ADU builder and garage conversion contractor, West Coast ADU handles a range of ADU types, including detached backyard structures, attached additions, garage conversions, and interior conversions such as basements or attics. Whether a homeowner is looking for a backyard cottage builder, a granny flat builder, or a Casita solution, West Coast ADU brings the expertise to deliver.

Costs for building an ADU can range from $50,000 to $350,000 or more, depending on the type, location, materials, and labor involved. Financing options such as home equity loans, construction loans, and cash-out refinancing may be available to eligible homeowners. West Coast ADU is committed to making the process transparent and accessible from start to finish.

Services

West Coast ADU performs the following services

  • Architecture & Design
  • Permit Specialist
  • Construction
  • Feasibility & Site Assessment
  • 3D renderings & floor plans

West Coast ADU Reviews

Damian Kuolt

2026-01-21
"Darron and Crew were better than I could have imagined. My plans were to do site development, foundations, utilities, setting the Manufactured ADU, etc., using separate, reliable, lowest bid contractors. But that plan changed as reality set in and virtually everything was handled by Darron. I previously worked in construction for 15 years, and did not expect to be 'won over' by anyone contractor. Bottom line, they were lowest bid, best positioned and most knowledgeable about all the 'other things' that were needed to complete every step. They were the best, most cost effective, so the handled everything from A to Z. The icing on the cake was how great a working relationship we developed and what a pleasure it has been to come to know Darron and his Team."

Justin Magnelli

2025-08-06
"Darron and his crew were amazing. They did such a wonderful job. Me and my family are so happy. They are very professional, and their quality of work is second to none."

Lisa Cruz

2024-10-24
"I had a friend refer me to this company. I can't say enough good things about them. I loved the professionalism of the company. They know what they're doing, and they will get the job done. If you ever want an ADU, this is the company to call"

Specifics

Prefab Specialist

Opening hours

Monday open 24h
Tuesday open 24h
Wednesday open 24h
Thursday open 24h
Friday open 24h
Saturday open 24h
Sunday open 24h

Location

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