10+ Years of Experience
ADU Builders
Mercer Island
Maksymov Brownstone LLC is the team homeowners call when an ADU has to fit a tight site, strict code, and a real construction budget at the same time.
As an ADU builder Mercer Island, WA clients trust, we design and build attached units, detached cottages, and site-specific layouts that work with the property.
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Our Expertise
Expert ADU Builder in Mercer Island: Maximize Your Property
An ADU on Mercer Island can solve two expensive problems at once: housing flexibility and underused land. It can create space for family, long-term guests, or rental income without pushing you into a full move. The catch is the site. On Mercer Island, lot work often runs straight into shoreline limits, watercourses, wetlands, or geohazard conditions like steep slopes, erosion, potential slide, and seismic areas. The city's process also treats ADUs as a land use review, not just a building permit.
What We Build in Mercer Island
- Custom Detached ADUs
- Attached Accessory Dwelling Units
- Garage-to-ADU Conversions
- Basement ADU Apartments
- Multi-Generational Living Suites
- Turnkey ADU Construction
- Custom design for your lot
- Full-service contractor support
Our Advantages
Why Mercer Island Homeowners Trust Our ADU Building Team
Local Mercer Island ADU Contractor
Our team handles Mercer Island permits and city-specific approvals daily, keeping projects compliant and moving without costly delays.
Upfront Cost Estimate
We break down the full build price before any work begins, so you can plan your budget confidently with no hidden fees.
Organized Project Timeline
From design to final inspection, your Mercer Island ADU stays on schedule through every phase of the build process.
Quality-Built ADU Homes
Every Mercer Island ADU we build uses durable materials and careful workmanship that meets local standards and stands the test of time.
Responsive Client Support
Quick replies and regular updates keep Mercer Island homeowners informed at every stage, from first consultation to final handover.
Proven Mercer Island ADU Builder
Homeowners in Mercer Island choose us for consistent results, completed projects and a track record that speaks for itself.
What We Build
ADU Services in Mercer Island
Homeowners in Mercer Island looking for a trusted ADU builder near me choose a team that understands local site conditions and Mercer Island city code. We deliver new builds and ADU remodels tailored to your specific lot, goals and budget.
Basement Conversion
Transform your underutilized basement into a self-contained ADU — fully legal, permitted, and designed for comfortable living in Mercer Island.
Garage Conversion
Convert your attached or detached garage into a stylish, code-compliant ADU unit in Mercer Island — often the fastest and most cost-effective path.
Attic Conversion
Maximize your Mercer Island home's vertical space with a beautifully finished attic ADU — ideal for rental income or a private guest suite.
Building an ADU in Mercer Island can feel overwhelming
Planning an ADU in Mercer Island comes with its own set of challenges — zoning rules, permits and tight budgets. Many homeowners feel uncertain about where to begin. With experienced accessory dwelling unit builders who know Mercer Island, the path forward becomes much clearer.
Where Do I Even Start?
The Mercer Island ADU process — design, city approvals, construction — can feel impossibly complex for first-time builders.
Hidden Costs
Unexpected fees and vague quotes leave homeowners over budget before construction even begins.
Delays & Unreliable Contractors
Missed deadlines and poor coordination drag projects on for years — costing time and money.
Lack of Clear Communication
Homeowners are often left in the dark, unsure of progress or next steps on their project.
Turning Mercer Island property potential into real, lasting rental income.
Client Reviews
What Our Clients Say
"I recently had the pleasure of working with Ihor on a remodeling project for my home, and I couldn't be happier with the results. From start to finish, Ihor demonstrated exceptional professionalism, skill, and attention to detail. Every concern we raised was addressed promptly, and the final result exceeded our expectations. Our new ADU looks incredible and was delivered exactly on time."
Jenny Lian
2 weeks ago
Portfolio
Recent ADU Projects in Mercer Island
University District Seattle Kitchen Renovation
How It Works
Our Process
Site Assessment
We review lot size, setbacks, access, utilities, and whether the property sits near shoreline, wetlands, watercourses, or geohazard areas before design starts.
Custom Design
Then we draw a unit that fits the main house and the site — rooflines, privacy, circulation, window placement, and grade transitions all get resolved here.
Permitting
We prepare the ADU submittal, code matrix, narrative, and plan set, then move the project through Mercer Island's Type II land use review process.
Construction
From foundation to framing to utility tie-ins, our crew builds the project in a clean sequence. Structure first. Weather-tight shell next. Then interiors.
Turnkey Delivery
After final inspections and sign-off, we complete the last details and hand over a finished ADU ready for family use, guests, or rental use.
Site Assessment
We review lot size, setbacks, access, utilities, and whether the property sits near shoreline, wetlands, watercourses, or geohazard areas before design starts.
Custom Design
Then we draw a unit that fits the main house and the site — rooflines, privacy, circulation, window placement, and grade transitions all get resolved here.
Permitting
We prepare the ADU submittal, code matrix, narrative, and plan set, then move the project through Mercer Island's Type II land use review process.
Construction
From foundation to framing to utility tie-ins, our crew builds the project in a clean sequence. Structure first. Weather-tight shell next. Then interiors.
Turnkey Delivery
After final inspections and sign-off, we complete the last details and hand over a finished ADU ready for family use, guests, or rental use.
About Us
Mercer Island's Leading Custom ADU Builders
Maksymov Brownstone LLC brings 17+ years of hands-on building experience to ADU work, and Mercer Island is not a city where you can fake that. A lot may look straightforward until the survey shows slope, the permit review flags a critical area, or the shoreline line changes what can be built.
The city specifically calls out watercourses, wetlands, erosion, steep slope, potential slide, and seismic hazards. Some properties also trigger shoreline permitting when work is within 200 feet of Lake Washington. We are a licensed and bonded team that works through those realities early.
Return on Investment
Why an ADU Is a Smart Investment in Mercer Island
Rental Income
In Mercer Island, a well-built ADU can generate $1,800–$3,200 per month. This consistent income helps offset the initial build cost, making your project financially sound over time.
Increase Property Value
Adding a permitted unit in Mercer Island can raise your home's value by $150,000–$300,000. With skilled accessory dwelling unit builders, this becomes a strong long-term gain.
Flexible Living Space
Build extra space for aging parents, adult children or a private office in Mercer Island. These custom homes on your property offer flexibility while keeping full ownership.
FAQ
Frequently Asked Questions About ADU Remodeling in Mercer Island
Planning an ADU project in Mercer Island comes with many questions about permits, timelines and budget. Below we cover the most common concerns homeowners have. Feel free to reach out for a personalized consultation and clear guidance specific to your Mercer Island property.
How much does it cost to build an ADU?
The cost depends on unit size, site work, utility connections, structural complexity, and finish level. A detached build usually carries more foundation and service work than a conversion. That is why early numbers can drift if the lot has slope, drainage, or access issues. We build estimates around the real property, not generic averages.
Can I build an ADU on my specific lot?
Maybe, but we do not guess. We check setbacks, access, utility routing, and whether the site is affected by shoreline limits, wetlands, watercourses, or geohazard areas. On Mercer Island, those constraints show up often enough that they have to be reviewed before design goes too far.
Why choose our company as your ADU builder?
Because ADU projects break down when design, permit work, and field construction are split between too many people. We keep the work under one roof, from feasibility through final inspection. That means fewer missed details, cleaner communication, and a finished unit that fits the site instead of fighting it.
Ready to Build Your ADU in Mercer Island?
Start with a free consultation — no pressure, just honest answers about your project.
Committed to superior quality and results
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Contact us
maksymov.brownstone@gmail.com
Phone
(425) 800-7663
Mon – Fri
9 am – 6 pm
Saturday
9 am – 1 pm