ADU & DADU Construction
Add living space, rental income, or room for family with a custom ADU or DADU. Russo Builders designs, permits, and builds backyard cottages and accessory units across Seattle and the Eastside — turnkey, code-compliant, and built to last.
WHAT WE OFFER
Detached DADU Construction
Ground-up construction of detached accessory dwelling units — backyard cottages designed and built as standalone homes. We handle site design, utilities, foundation, framing, and finishes for a fully independent living space with its own entrance, kitchen, and bath.
Attached ADU Construction
Attached ADUs built as additions to your main home — connected living space with a private entrance, kitchenette, and bath. Ideal for multi-generational living, guest space, or rental income without giving up yard space.
Garage & Basement Conversion
Conversions of existing garages and basements into legal, code-compliant ADUs. We handle insulation, egress, plumbing, electrical, and permitting to transform underused space into income-generating living space.
ADU Design & Permitting
Complete design and permit navigation for Seattle, Bellevue, Kirkland, and King County. We produce drawings, submit applications, and shepherd your ADU through zoning, environmental, and building permits — including the Seattle ADUniverse and pre-approved DADU programs.
Studio & One-Bedroom ADUs
Compact, efficient ADU layouts — from 200 sqft studios to 800 sqft one-bedroom cottages. Designed for maximum livability with vaulted ceilings, built-in storage, and smart layouts that make small spaces feel generous.
Rental-Ready Finish Packages
Durable, tenant-ready finish packages engineered for long-term rental use. Hard-wearing floors, solid-surface counters, quality fixtures, and easy-to-maintain finishes that hold up to tenants and reduce turnover and repair costs.
Build Income
In Your Backyard.
Washington State and the City of Seattle have made it easier than ever to build an accessory dwelling unit on your property. An ADU or DADU adds livable square footage, multi-generational living space, or steady long-term rental income — all without buying more land.
Russo Builders is a full-service ADU builder. We handle the entire process — site evaluation, design, permitting, utility connections, foundation, framing, MEP, and finishes — so you get a turnkey, code-compliant unit ready to live in or rent. We know the Seattle ADUniverse pre-approved DADU program, King County zoning, and Eastside permit processes inside and out.
Serving homeowners across Seattle, Bellevue, Kirkland, Redmond, Medina, Sammamish, Issaquah, Newcastle, Renton, and Mercer Island, we bring 25+ years of residential construction experience to every ADU project. Call (425) 306-5553 to start yours.
WHAT SETS US APART
Backyard
Cottages.
ADU Questions
Answered.
How much does an ADU cost to build in Seattle?
Detached DADUs typically range from $150,000–$400,000+ depending on size, site conditions, utilities, and finishes. Attached ADUs and garage conversions are usually less. We provide detailed estimates after a site visit and design consultation.
How long does it take to build an ADU?
Permitting takes 2–6 months depending on jurisdiction and whether you use a pre-approved plan. Construction typically takes 4–8 months from foundation to final inspection. We provide a firm timeline during the planning phase.
Do I need a permit for an ADU?
Yes. ADUs and DADUs require building permits, and often zoning, environmental, and utility permits. Russo Builders handles the entire permit process in-house, including Seattle’s ADUniverse pre-approved DADU program and King County permitting.
What is the difference between an ADU and a DADU?
An ADU (accessory dwelling unit) is attached to or within the main home. A DADU (detached accessory dwelling unit) is a standalone structure in the backyard. Both are fully self-contained with kitchen and bath. We build both.
Can I rent out my ADU?
Yes. ADUs are legal rental units in Seattle and most Eastside jurisdictions, providing long-term rental income. Short-term rentals have additional rules. We design and build ADUs optimized for rental use with durable, tenant-ready finishes.
What areas do you serve for ADU construction?
We serve Seattle and the entire Seattle Eastside, including Bellevue, Kirkland, Redmond, Medina, Sammamish, Issaquah, Newcastle, Renton, and Mercer Island. Call (425) 306-5553 to confirm your area.
Ready to
Build an ADU?
Tell us about your property and goals. We will help you design, permit, and build an ADU that fits your lot and your plans.