ADU Contractors near Mercer Island, WA
Seattle ADU
509 Olive Way, Seattle, WA 98101
5.8 miles
Seattle ADU is a Seattle-based contractor specializing in accessory dwelling units, including detached ADUs, garage conversions, attached ADUs, and JADUs. They manage design, permitting, and construction for homeowners seeking additional living sp... read more
NW Finishing
2265 116th Avenue Northeast, Bellevue, WA 98004
4.9 miles
NW Finishing is a Seattle-area ADU contractor offering full-service accessory dwelling unit design and construction. Serving Bellevue, Kirkland, Redmond, Renton, and more, they handle permits, planning, and builds for detached, cottage, and prefab... read more
Anderbar Construction
12391 Glenwood Road Southwest, Port Orchard, WA 98367
23.1 miles
We specialize in building high-quality, custom Accessory Dwelling Units (ADUs) that provide both functionality and style for homeowners in Port Orchard, WA, and the surrounding areas. Whether you’re looking to add a rental property, create a coz... read more
Greater Seattle Remodeling
1850 130th Ave NE #1, Bellevue, WA 98005
4.8 miles
Greater Seattle Remodeling builds code-compliant ADUs across the Seattle metro, including detached ADUs, garage conversions, and basement apartments. They match homeowners with vetted contractors for permits, design, and construction.
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H26 Builders
5207 South Willow Street, Seattle, WA 98118
2.4 miles
H26 Builders is a Seattle ADU contractor offering attached ADUs, detached ADUs, and garage conversions. Services include design consultation, permitting support, and project management to help homeowners add functional living or rental space.
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HiLine Homes
11306 62nd Avenue East, Puyallup, WA 98373
25.3 miles
HiLine Homes is an experienced ADU builder in Idaho with nearly 30 years in custom home construction. They offer attached and detached ADU designs for rental income, multigenerational living, or home offices, with financing options available.
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Northwest ADU
1201 Pacific Avenue, Tacoma, WA 98402
23.7 miles
Northwest ADU is a full-service ADU contractor in Western Washington specializing in detached ADUs, garage conversions, and basement conversions. Serving Pierce, King, and Snohomish Counties, projects range from $180K–$350K+, taking 6–10 month... read more
Northwest Builders & Renovation
1135 Lake Washington Boulevard North, Renton, WA 98057
4.6 miles
Huskies Construction
1201 Monster Road Southwest, Renton, WA 98057
6.7 miles
Huskies Construction in Renton specializes in home additions, ADUs, and DADUs. Services include garage conversions, granny flats, in-law suites, backyard cottages, and room additions, helping homeowners expand living space or generate rental incom... read more
Ballard Backyard Cottages
4142 2nd Avenue Northwest, Seattle, WA 98107
8.6 miles
Seattle's trusted DADU & ADU builder offers custom builds, ADU conversions, and prefab cabins. Transparent pricing, expert guidance, and hands-on construction help homeowners add lasting value with backyard cottages and granny flats.
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New Image Construction Management
8305 Dallas Avenue South, Seattle, WA 98108
4.8 miles
New Image Construction Management is a Washington State general contractor and building company based in Seattle, WA. With a primary focus of new home construction and renovation of residential and commercial properties.
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Alta Group Seattle
500 Southeast Everett Mall Way, Everett, WA 98208
23.7 miles
Homez Remodel
13213 Southeast 278th Street, Kent, WA 98042
15.1 miles
Homez Remodel is a Seattle ADU builder specializing in DADUs, backyard cottages, garage conversions & basement ADUs. With 10+ years experience, they handle permits, design & construction across Seattle, Bellevue, Kirkland & more.
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North West Builders & Renovations
1135 Lake Washington Boulevard North, Renton, WA 98057
4.6 miles
FTS Excavation
12714 151st Street East, Puyallup, WA 98374
30.9 miles
FTS Excavation offers full-service ADU site development in South Puget Sound, Western Washington. Services include grading, utilities, septic systems, foundation excavation & permits. Certified, reliable ADU contractor for backyard homes &... read more
Other cities in Washington
What you need to know
Building ADUs on Mercer Island: Navigating a Unique Island Community
Mercer Island, Washington, is a distinctive residential community situated entirely on an island in Lake Washington, connected to Seattle and Bellevue via Interstate 90. This unique geography creates specific challenges and opportunities for ADU contractors in Mercer Island. The city is known for its affluent, tree-lined neighborhoods, strict environmental protections, and limited land availability — all factors that make accessory dwelling units (ADUs) an increasingly attractive solution for homeowners looking to maximize their property's potential.
Mercer Island ADU Regulations and Zoning Requirements
Before breaking ground, experienced Mercer Island ADU contractors must be well-versed in the city's specific zoning codes and building regulations. Mercer Island falls under King County jurisdiction for some matters but maintains its own municipal code. Key regulations homeowners and contractors need to understand include:
- ADU size limits: Detached ADUs (DADUs) are generally limited in square footage relative to the primary dwelling size.
- Setback requirements: Mercer Island enforces strict setback rules, particularly important given the island's many sloped and waterfront lots.
- Tree retention policies: The city has robust tree protection ordinances that ADU contractors must carefully navigate during site planning and construction.
- Critical areas regulations: Proximity to Lake Washington and various wetlands means many properties fall within critical area buffers, requiring additional environmental review.
- Owner-occupancy rules: Homeowners should verify current owner-occupancy requirements, which may affect rental ADU plans.
Types of ADUs Commonly Built in Mercer Island
Given the island's predominantly single-family residential character and lot configurations, ADU builders in Mercer Island, WA most frequently work on the following project types:
- Attached ADUs: Additions connected to the main home, ideal for lots with limited buildable area.
- Detached ADUs (DADUs): Separate backyard cottages or garage conversions, popular in larger Mercer Island lots.
- Interior ADUs (JADUs): Basement or ground-floor conversions within the existing home footprint, minimizing site disturbance.
Why Hire a Local ADU Contractor in Mercer Island?
Working with a licensed ADU contractor familiar with Mercer Island is essential for a smooth permitting and construction process. Local contractors understand the nuances of building on island terrain, including managing utility connections, dealing with the city's permit office, and respecting the community's high aesthetic standards. Mercer Island homeowners consistently prioritize quality craftsmanship and design that complements the area's natural beauty and upscale character.
Start Your Mercer Island ADU Project Today
Whether you're looking to create a rental income unit, house family members, or increase your property value, an ADU is a smart investment in Mercer Island's competitive real estate market. Connect with a qualified ADU contractor serving Mercer Island, Washington to discuss your project goals, review local code requirements, and begin the design and permitting process with confidence.