Modern, site-built backyard homes designed for Northwest living.

At Emerald State Contracting, we specialize in designing and building high-quality ADUs and DADUs across Seattle, Bellevue, Renton, Tacoma, and surrounding communities. Whether you’re creating space for family, adding a rental unit, or investing in your property long-term, we help you build a modern backyard home that fits your lifestyle, budget, and lot conditions.

Unlike prefab structures, our ADUs are fully site-built with long-lasting materials, proper foundations, full utility connections, and custom finishes. Every project is engineered, permitted, and constructed to meet (and often exceed) Washington building codes.

We offer ADUs in multiple sizes and layouts:

  • 300–350 sq ft studio suites and backyard offices

  • 400–600 sq ft one-bedroom ADUs

  • 700–900 sq ft two-bedroom units

  • 1,000–1,200 sq ft full-size backyard homes

Plans can be adapted for guest suites, multigenerational living, home offices, rental units, wellness rooms, creative studios, or fully independent small homes.

Every ADU includes:

  • Concrete foundation or slab-on-grade system

  • Full framing + engineered structural components

  • High-performance insulation + air sealing

  • Modern siding (cedar, fiber cement, or stucco)

  • Energy-efficient windows + doors

  • Standing-seam metal or architectural shingle roofing

  • Complete electrical, plumbing, and HVAC systems

  • Full kitchen or kitchenette options

  • Modern bathrooms

  • Drywall, flooring, trim, and finish carpentry

We build ADUs the same way we build full homes: with durability, comfort, and long-term value at the forefront.

For homeowners who want a higher architectural look, we also offer:

  • Corner glazing + large-format window systems

  • Cedar soffits with integrated LED lighting

  • Level 5 smooth drywall

  • Premium siding packages

  • Radiant floor heating

  • Modern stucco or metal panel exteriors

  • Custom cabinetry + millwork

  • Premium tile + bathroom fixtures

You can keep it simple — or make it stunning. You choose.

We guide you from the first conversation through the final inspection:

1. Feasibility & Site Review

We verify setbacks, utilities, slope, access, existing structures, and local zoning. AHERA asbestos inspection available for older homes.

2. Design Support & Plan Selection

Choose from our model ADUs (300, 600, 900, 1200 sq ft) or work with us to tailor the footprint and finish level to your needs.

3. Permitting & Engineering

We prepare construction drawings, structural engineering, and required permitting documentation.

4. Construction

Full foundation-to-finish building with clear communication and daily progress updates.

5. Final Inspection & Handover

We deliver a clean, turn-key ADU ready for guests, family, or tenants.

Licensed, bonded, insured

  • AHERA-certified asbestos inspector for safe demo

  • Lead-safe certified (RRP)

  • Clear, honest communication (no upselling, no pressure)

  • High-quality craftsmanship with modern details

  • Local builder who understands Northwest conditions

  • Flexible design and finish options

Our goal is simple: build you a beautiful, durable ADU that fits your property and stands the test of time.

Contact us.

info@emeraldstatecontracting.com
(425)336-9772