Premier Seattle ADU & DADU Builders: From Concept to Completion
Transform your property with a custom-built backyard cottage. Whether you’re looking for rental income or a multi-generational living space, our expert team handles everything from local King County permitting to high-end interior finishes.
- Fully Permitted ADUs in Washington
- Built Green™ Certified Builder
- Comprehensive 12-Month Warranty
- Transparent Timeline & Pricing
Recent ADU & DADU Projects
See how we transform underutilized spaces into functional, high-quality living environments.
BEFORE
AFTER
BEFORE
AFTER
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Why Choose Us as Your ADU Contractor?
- Licensed, Bonded & Insured ADU Builders
- Built Green™ Certified Construction
- Full Design-Build Team (No Hand-Offs)
- Transparent Communication with BuilderTrend
- Family-First, Client-Focused Approach
Serving Seattle & Surrounding Areas
We build ADUs/DADUs across:
- Seattle
- Lynnwood
- Edmonds
- Kirkland
- Bellevue
- Bothell
- Woodinville
How Much Does an ADU Cost in Washington?
Accessory Dwelling Unit (ADU) costs vary depending on size, design, and site conditions. Here are typical ranges:
- Detached ADU (DADU): $150,000 – $350,000+
- Garage Conversion ADU: $80,000 – $180,000
- Attached ADU: $100,000 – $250,000
We provide transparent estimates and help you understand what’s possible based on your property and budget
Meet the Team
Our team at MacCoy Home Solutions consists of dedicated professionals committed to delivering exceptional results and customer service.
Aaron MacCoy
Owner
Marie MacCoy
Owner
Bill Hurley
Sales Coordinator & Safety Manager
Kyle Olson
Project Manager
Ariadna Delgado-Trahen
Office Assistant
Derek Collins
Project Manager
Harold Stjern
Field Supervisor
Steven White
Lead Carpenter
Donny Arndt
Lead Carpenter
Jordan Behrens
Carpenter
Frequently Asked Questions
Are ADUs legal in Lynnwood?
Yes. With the right permits, ADUs and DADUs are allowed in most residential zones.
How much does an ADU cost in Lynnwood?
Costs vary based on design, utilities, and site conditions. We provide transparent estimates after assessment.
Can ADUs be used as rentals?
Yes—many homeowners build ADUs for long-term rental income.
Do ADUs increase property value?
Often significantly, especially when professionally designed and built.
Ready to Build Your ADU?
Work with a trusted ADU builder who handles everything—from concept to completion.