Granny Flat Builder Inland Northwest Colbert, Washington
Detached & attached ADUs built for Spokane lots, families, and rental income
Accessory Dwelling Units (ADUs) Service in Colbert, Washington
ADU Construction in Spokane & the Inland Northwest
An accessory dwelling unit is a self-contained second home on your property — complete with its own kitchen, bathroom, and living space. Stonegate Builders is a licensed general contractor in Spokane, and we build ADUs for homeowners across the greater Spokane area, Spokane Valley, Liberty Lake, and Mead. As homeowners look for flexible, cost-conscious ways to add usable square footage, a well-built ADU can be one of the most practical investments you make in your property. Whether you want a private space for aging parents, a home office, or a long-term rental, we manage the project from first sketch to final inspection.
You get it, the subject of accessory dwelling units (adus) is just one of those things in life you have to trust a professional to do. So feel free to skip all the reading and click the button below to get a quote now, or scroll down to learn more.
Get A QuoteTypes of ADUs We Build
Every property is different, so we help you choose the format that fits your lot, budget, and goals:
- Detached ADUs (DADUs) — standalone backyard cottages separated from the main house, ideal for privacy and rental use.
- Attached ADUs — additions connected to your existing home, often used as in-law suites or multigenerational quarters.
- Garage conversions — transforming an existing garage or shop into finished, insulated living space.
- Basement and interior conversions — reworking underused square footage into a legal, private unit.
Our Process, Step by Step
- Consultation — we walk your property, discuss how you plan to use the space, and talk through realistic options.
- Design & feasibility — we develop a layout that suits your lot, setbacks, and utility connections.
- Permitting — we prepare and submit plans for City of Spokane or Spokane County review and coordinate required inspections.
- Site work & foundation — excavation, footings, and a foundation engineered for our regional freeze-thaw cycles.
- Framing, systems & finishes — framing, electrical, plumbing, insulation, and interior finishes completed to code.
- Final walkthrough — we verify every detail with you before you take the keys.
Materials & Options
We build ADUs to match your main home or stand confidently on their own. Options include fiber-cement or engineered siding, energy-efficient windows, upgraded insulation packages, and low-maintenance roofing rated for snow load. Interiors can feature durable flooring, quartz countertops, and efficient heating and cooling sized for a compact footprint. Where it suits your plans, we can also design for single-level access and wider doorways so the space works comfortably at every stage of life. Because masonry and stonework are a genuine specialty of ours, we can integrate brick, block, or natural and manufactured stone accents that tie the unit to your property with strength and precision.
Spokane Permitting & Climate Considerations
ADU rules vary by jurisdiction, and requirements around size, setbacks, parking, and owner-occupancy continue to evolve. We help you navigate Spokane-area zoning and permitting in practical terms and build to current code. Our region's cold, snowy winters demand serious attention to insulation, snow load, and freeze-thaw durability — details we plan for from the foundation up so your ADU stays comfortable and energy-efficient year-round.
Why Choose Stonegate Builders
We are a licensed, bonded, and insured Washington contractor built on strength, precision, and trust. You get clear communication, careful craftsmanship, and a team that understands Inland Northwest construction and the local approval process. From the first conversation to the final inspection, we keep you informed and involved, and we hold every ADU to the standards we would want for our own family. We treat your ADU as an investment in your property — not just another job.
Common Uses for Your New ADU
- Multigenerational living and in-law suites
- Long-term rental income or a private guest space
- A home office, studio, or flexible work-from-home retreat
- Housing for adult children or caregivers close to home
Ready to explore what an ADU could look like on your Spokane-area property? Call Stonegate Builders today at (509) 609-5199 to schedule your consultation and take the first step toward smart, lasting added living space.
Accessory Dwelling Units (ADUs) FAQs
We serve the greater Spokane area and the Inland Northwest, including Spokane Valley, Liberty Lake, Mead, Cheney, Deer Park, and surrounding communities. If you are unsure whether your location is within our service area, give us a call and we will let you know and discuss next steps for your ADU.
Timelines depend on the ADU type, site conditions, design complexity, and how long permitting takes in your jurisdiction. A garage conversion generally moves faster than a detached unit with new foundations and utilities. After we review your property and goals, we can give you a realistic schedule for your specific project.
Our Inland Northwest winters call for careful planning around insulation, snow load, and freeze-thaw durability. We engineer the foundation for local soil and frost conditions, use upgraded insulation and energy-efficient windows, and select roofing rated for snow. The result is a compact home that stays warm, comfortable, and efficient through cold, snowy seasons.
Absolutely. We can match your roofline, siding, and finishes so the ADU looks like a natural extension of your property, or give it a distinct character if you prefer. Because masonry is a core specialty of ours, we can also add brick, block, or stone accents that tie the new unit to your home with a consistent, quality look.
An ADU gives family members a private, independent living space while keeping them close by. It is a popular option for aging parents, adult children, or live-in caregivers who want their own kitchen and bathroom yet remain steps from the main home. We can design layouts with accessibility and comfort in mind for every stage of life.
In many cases, yes. Homeowners often use ADUs for long-term rental income, guest housing, or a private space for family. Local rules on rentals, occupancy, and short-term stays vary and continue to change, so we encourage you to confirm current requirements for your area. We build the unit to code so it is ready for your intended use.
Yes. ADUs require permits and must meet local zoning and building codes, whether your property falls under the City of Spokane or Spokane County. As a licensed general contractor, we prepare and submit your plans, coordinate the required inspections, and build to current code so the project stays on solid footing from start to finish.
We build detached ADUs (also called DADUs or backyard cottages), attached units connected to your existing home, garage conversions, and basement or interior conversions. During your consultation we help you weigh privacy, cost, and how you plan to use the space so you can choose the format that best fits your Spokane-area property.
An accessory dwelling unit is a complete, self-contained second home on your property, with its own kitchen, bathroom, and separate entrance. A standard addition simply expands your existing house. An ADU can function fully on its own, which makes it well suited for rental income, guests, or multigenerational living while remaining part of your lot.