What Is an ADU?

An accessory dwelling unit (ADU) is a fully functional secondary residence located on the same property as a primary home. ADUs include their own kitchen, bathroom, living space, and sleeping area, making them ideal for independent living.

In West Linn, ADUs have become one of the most strategic ways to increase property utility without relocating. With rising home values and a strong demand for flexible housing, homeowners are using ADUs to future-proof their properties.

Types of ADUs We Build

Detached ADUs (Backyard Cottages)
Standalone structures that offer maximum privacy and flexibility. Ideal for rental units, guest houses, or long-term family use.

Attached ADUs (Additions)
Integrated into the main home, these units are great for maintaining close proximity while still providing separation.

Garage Conversions
Transform underutilized garages into livable space with lower structural costs than new builds.

Basement ADUs
Leverage existing square footage to create a cost-effective living space within your home’s footprint.

Why West Linn Homeowners are Building ADUs

West Linn offers a unique combination of suburban comfort, strong property values, and increasing housing demand, making it an ideal environment for ADU investment.

Generate Long-Term Rental Income

ADUs can provide consistent monthly income in a high-demand market. Whether used for long-term tenants or extended family, they create financial flexibility and offset mortgage costs.

Support Multigenerational Living

More homeowners are choosing to house aging parents, adult children, or extended family members on their property. ADUs allow for independence while keeping loved ones close.

Increase Property Value

A well-designed ADU can significantly increase resale value and market appeal, especially in desirable areas like West Linn.

Adapt to Changing Needs

From home offices to guest suites to future downsizing options, ADUs provide unmatched flexibility over time.

Why Choose Lamont Bros. Design & Construction as Your West Linn ADU Builder?

Choosing the right builder directly impacts your project’s outcome. Lamont Bros. brings a proven, structured approach to ADU design and construction.

  • Integrated design-build model for better coordination and accountability
  • Deep experience with local permitting in West Linn and surrounding areas
  • Transparent pricing and process with no surprises
  • High-quality craftsmanship backed by a portfolio of completed projects
  • Client-first communication throughout every phase

We focus on delivering not just a finished structure, but a long-term asset that enhances your home and lifestyle.

Lamont Bros. Design & Construction

West Linn | ADU Builder Portfolio

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Clackamas Crawlspace Conversion
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Start Planning Your West Linn ADU

Thinking about building an ADU in West Linn? Whether you're exploring options or ready to move forward, our team is here to help you take the next step with clarity and confidence.

At Lamont Bros. Design & Construction, we use a design-build approach that brings your entire project—design, planning, and construction—under one team. This creates a more streamlined process, better communication, and more predictable results.

You won’t be left coordinating between designers, contractors, and the city. We handle it all.

What to Expect When You Reach Out

  • A conversation with an experienced ADU design-build professional: Talk through your ideas, goals, and how you want to use your space.
  • Clarity on your property’s potential: We’ll help you understand what’s feasible based on your lot, layout, and West Linn zoning requirements.
  • Guidance on costs and timelines: Get realistic expectations for budget ranges, project scope, and how long the process may take.
  • Next steps tailored to your project: Walk away with a clear understanding of how to move forward—no guesswork.

 Fill out the form to connect with a design-build expert and start planning a project tailored to your property, goals, and budget. 

Request a Consultation

West Linn | ADU Builders

Frequently Asked Questions

How much does it cost to build an ADU in West Linn, Oregon?

The cost to build an ADU in West Linn typically ranges from $200,000 to $400,000+, depending on size, design complexity, site conditions, and whether it’s detached or a conversion. Custom ADUs with high-end finishes or challenging sites can exceed this range.

Read more here: 4 Common Types of ADUs and What They Cost

Do I need a permit to build an ADU in West Linn?

Yes, you must obtain permits from the City of West Linn before building an ADU. This includes zoning review, building permits, and inspections to ensure the structure meets local codes and safety requirements.

Lamont Bros. Design & Construction handles all permits for any projects we work on.

Can I rent out an ADU in West Linn?

Yes, ADUs in West Linn can typically be rented as long-term housing.

Short-term rental rules may vary, so it’s important to confirm current city regulations before planning to use the unit as a vacation rental.

How long does it take to build an ADU in West Linn?

Building an ADU in West Linn usually takes 9 to 14 months from design through construction.

The timeline depends on permitting speed, project complexity, and site conditions.

What types of ADUs can be built in West Linn?

Common ADU types in West Linn include detached backyard cottages, attached ADUs (home additions), garage conversions, and basement apartments. The best option depends on your property layout and goals.

Is my property eligible for an ADU in West Linn?

Most single-family residential properties in West Linn are eligible for at least one ADU, but factors like zoning, lot size, utility access, and existing structures will determine feasibility.

What is the process for building an ADU with Lamont Bros.?

The ADU process typically includes feasibility, design, permitting, and construction, all managed under a design-build approach. This integrated process helps reduce delays, control costs, and streamline communication.

Can an ADU increase my property value?

Yes, adding an ADU can increase property value by adding livable square footage and creating rental income potential. The exact impact depends on design quality, location, and market conditions.

Do ADUs require separate utilities in West Linn?

ADUs may share utilities with the main home or require separate connections, depending on design and local requirements. Water, sewer, and electrical planning are key parts of the early design phase.

The Lamont Bros. Difference

Award Winning Craftsmanship

Lamont Bros. has earned recognition as a multi-award-winning Portland design-build firm, including the NARI Remodeler of the Year award and Houzz Best Service every year since 2016.

Client-Verified Excellence

Lamont Bros. maintains a 4.8-star average rating across Google, Houzz, and Yelp, reflecting consistent client satisfaction across hundreds of completed remodeling projects.

20 Years of Experience

Since 2008, Lamont Bros. has completed 850+ remodeling projects across the Portland metro area, including kitchens, bathrooms, additions, and ADUs in Portland, Beaverton, Lake Oswego, West Linn, and Oregon City.