ADU Contractors near Mercer Island, WA
Seattle ADU Builders
4138 Baker Avenue Northwest, Seattle, WA 98107
8.7 miles
Emerald ADU Builders Seattle specializes in ADU design, permitting, and construction. They build detached ADUs, attached ADUs, and garage conversions, serving Seattle homeowners with quality craftsmanship and transparent pricing.
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Deane Home Services
17837 1st Avenue South, Normandy Park, WA 98148
9.8 miles
Deane Home Services builds ADUs in South King County, WA, including garage conversions, basement remodels, and detached backyard cottages. Licensed, bonded & insured. Serving Kent, Renton, Federal Way & more.
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Northwest ADU Builders of Mill Creek
6100 219th Street Southwest, Mountlake Terrace, WA 98043
15.6 miles
Northwest ADU is a trusted ADU builder in Mill Creek, WA, offering full-service accessory dwelling unit construction, including detached ADUs, garage conversions, and basement conversions, with expert permit and zoning support.
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BB Builders Pro
801 Southwest 16th Street, Renton, WA 98057
7 miles
BB Builders Pro specializes in ADU construction, garage conversions, home additions, and detached backyard cottages. Services include custom design, permitting, zoning compliance, and renovations—ideal for rental income or family housing.
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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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BelRed Construction - Bathroom Remodeling
13629 Northeast Bel Red Road, Bellevue, WA 98005
4.6 miles
Our team specializes in ADU construction and home remodeling, creating functional, well-designed spaces with quality craftsmanship and attention to detail.
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Puget Sound ADU Builders
4712 South Morgan Street, Seattle, WA 98118
2.4 miles
Puget Sound ADU Builders is a leader in ADU construction in western Washington state, excelling in design, construction, finishing, and permitting ADUs, DADUs, backyard cabins, garage conversions, duplexes, town homes, and multi-unit projects.
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Gordon T. Jacob - Multifamily | DADU | Remodel
6901 81st Street Court East, Puyallup, WA 98371
27.6 miles
Gordon T. Jacob is a family-run ADU builder and home remodeling contractor in South Puget Sound. Specializing in detached ADUs, backyard cottages, middle housing, and full home renovations in the Tacoma area.
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Era Builders
911 Northeast 70th Street, Seattle, WA 98115
8.8 miles
Era Builders is a Seattle-based ADU contractor offering detached ADU construction, design, permitting, remodeling, and commercial renovations. They handle full ADU projects compliant with Seattle zoning rules, using sustainable practices.
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Avead
3600 136th Place Southeast, Bellevue, WA 98006
3.7 miles
Avead is an ADU contractor offering full-service accessory dwelling unit construction, including attached, detached, junior ADUs, garage conversions, and custom builds. With 20+ years of experience, transparent pricing, and a 5-year warranty.
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DIGS Construction & ADU Builders
18727 North High Rock Road, Monroe, WA 98272
22.3 miles
DIGS is a trusted ADU builder serving King & Snohomish County, WA. They offer custom ADU/DADU design, permitting, construction, and site development, helping homeowners add rental income, property value, and flexible living space.
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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
Model Remodel
1111 West Nickerson Street, Seattle, WA 98119
8.9 miles
Seattle's 2019 ADU law changes made it easier to build accessory dwelling units on single-family lots. DADUs can't exceed 50% of the main home's size. No parking required. New detached ADUs start around $350,000.
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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
Cast Architecture
115 North 36th Street, Seattle, WA 98103
8.3 miles
Cast Architecture specializes in ADU and backyard cottage design in Seattle since 2009. With 80+ projects, their Cedar Cottage is pre-approved by Seattle & Kirkland. Award-winning designs include Widner Cottage and Lichtenstein Studio. Visit c... 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.