Services
ADU Builders in Portland, OR
Looking to add functional living space, create rental income, or build an independent home for additional family members? Marsh Design Build provides full-service ADU design, planning, and construction across the Portland–Vancouver metro.
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As experienced ADU builders in Portland OR, we guide homeowners through feasibility, design, permitting, and construction with a unified process that keeps projects clear, compliant, and on schedule. Our ADUs are built for long-term comfort, performance, and value.
Design, Planning & Development
A feasibility-first approach that keeps projects on track
Your ADU begins with understanding what your property can support. We conduct zoning and code research, evaluate site access and utilities, and identify any structural or permitting considerations before design work begins.
Our design and planning phase typically includes:
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Site review and feasibility studies
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Zoning and building code analysis
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As-built documentation (if required)
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Architectural design and layout development
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3D visualizations
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Structural and engineering coordination
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Construction drawings
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Permit preparation and support with local jurisdictions
This integrated approach removes guesswork and ensures your ADU moves smoothly from concept into construction.
How an ADU Can Enhance Your Property
Flexible, functional space designed for long-term use
ADUs are self-contained units built on the same lot as your primary home. Homeowners use them for:
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Private housing for parents or adult children
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Rental income or long-term tenants
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Guest accommodations
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Future aging-in-place planning
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Increasing overall property value
We help create an ADU that fits your goals and feels like a natural extension of your property.
Why Homeowners Choose Marsh Design Build & Our Roadmap
A unified ADU process from first conversation to final walkthrough
Homeowners choose Marsh Design Build because our design build model eliminates the disconnects common in ADU projects. With one accountable team, every phase—design, permitting, and construction—moves forward with clarity.
Here is how our structured roadmap works:
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Consultation & Site Review
We meet to discuss goals, walk your property, and identify opportunities, constraints, and zoning considerations.
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Feasibility & Concept Direction
We outline what can be built, where it can go, and what size/layout options make sense for your site.
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Concept Design & Cost Alignment
We develop initial layouts and exterior direction while aligning material and structural decisions with realistic budgets.
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Detailed Design & Permitting
We finalize architectural plans, coordinate engineering, prepare permit-ready drawings, and guide you through submittal.
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Construction & Project Management
Once permits are approved, we manage the full build—site prep, framing, systems installation, finishes, inspections, scheduling, and daily oversight.
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Final Walkthrough & Completion
We finish all punch-list items, verify performance, and deliver a fully completed, move-in-ready ADU.
Where We Build ADUs
We design and build ADUs throughout the Portland–Vancouver metro, including:
🚩 Portland, OR
🚩 Vancouver, WA
🚩 Beaverton
🚩 Tigard
🚩 Gresham
🚩 Camas
🚩 Milwaukie
🚩 Happy Valley
🚩 Hillsboro and surrounding communities
This regional experience helps us navigate local zoning, permitting, and structural requirements with precision.
Start Your ADU With Marsh Design Build
Explore what’s possible on your property
If you’re considering an ADU, our team can help you understand feasibility, cost ranges, timeline expectations, and the steps needed to move forward confidently.
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Schedule an ADU Consultation
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Your ADU begins with one conversation—and we’re here to guide you from concept to completion.