Accessory Dwelling Units
Maximize your property footprint with modern detached ADUs, attached suites, and garage conversions engineered for rental income, multi-generational living, or backyard retreats.
Expand and Utilize Space: Washington ADU Contractors
There are many reasons to invest in an ADU (Accessory Dwelling Unit). Many find that these spaces are a smart way to expand their living space, create room for their aging parents, host guests, or make additional income. However, undertaking an ADU project on your own can be extremely overwhelming and complicated.
The experts at Capitol Custom Construction have the local code knowledge (including Washington State’s HB 1337 ADU mandates), construction ability, and attention to detail required for a successful ADU build. Looking specifically for Tumwater permitting details? Visit our dedicated ADU Builder in Tumwater, WA guide.
- Permitting Handled End-to-End: We are knowledgeable about the complicated processes for obtaining the right permits to start work. We take care of the red tape so you don’t have to worry about it.
- Property Value & Income: ADUs increase property value and, in many cases, serve as additional income for families and homeowners. Building an ADU is a smart way to provide financial security.
- Detached, Attached & Garage Conversions: Depending on your property type, we assist with garage or basement conversions, stand-alone units, and attached units. We consult with you to find the best ADU fit for your property and life circumstances.
Functional, Modern, and Quality ADU Builders
We take you through the ADU building process from start to finish, leaving you with no unanswered questions or in the dark about your ADU project. We thoroughly explain every process, from permitting, code, and construction to completion.
- Lot Feasibility & Zoning Audit: Setback verification, lot coverage limits, water table check, and sewer vs. LOTT/septic evaluation.
- Custom ADU Design & Engineering: Full architectural and structural plans tailored to your parcel.
- Turnkey Utility & Site Construction: Trenching and foundation, framing, roofing, siding, electrical, plumbing, drywall, countertops, and final occupancy inspection.
Why Homeowners Partner With Capitol Custom Construction
- Professional Contractors: Entrust your next project to contractors who have been in the game for years and have the know-how to execute your dream build.
- Licensed and Insured: Our contractors are licensed and insured experts. Our work is done at the highest safety standards.
- We Fill Any Need: Our services range from new home construction to general home projects. Whatever your build is, we can do it.
- Honest and Trustworthy: No surprise work, fees, or flaky contractors here. We communicate clearly and deliver what we promise.
Ready to Start Your Accessory Dwelling Units Project?
Partner with honest, transparent, straight-to-the-point contractors. Proud members of the Olympia Master Builders serving Tumwater, Olympia, Lacey, and 20 communities across Western Washington.
Accessory Dwelling Units — Featured Photos
Project Portfolios Featuring Accessory Dwelling Units
Powell Barn Custom Build
High-volume custom barn and living structure featuring heavy timber/structural framing, lofty vaulted drywall interiors, and a fully waterproofed custom tile bathroom.
Miscellaneous Projects & Craftsmanship Gallery
A curated collection of recent Capitol Custom Construction builds—including Washington ADU installations, custom cedar and composite decks, luxury kitchen and bathroom remodels, and heavy site excavation.
No Hand-Offs, No Excuses. Built Around You and Built to Last Across Western Washington.
Start Your Project TodayYour Next Custom Home Builders
Professional Contractors
Entrust your next project to contractors who have been in the game for years and have the know-how to execute your dream build.
Licensed and Insured
Our contractors are licensed and insured experts. Our work is done at the highest safety standards.
We Fill Any Need
Our services range from new home construction to general home projects. Whatever your build is, we can do it.
Honest and Trustworthy
No surprise work, fees, or flaky contractors here. We communicate clearly and deliver what we promise.