Maximize Your Property’s Potential with a Beautifully Designed ADU

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From income opportunities to multigenerational living, our ADUs are crafted for Lewiston and the Palouse.

  • Income Stream

    Adding an ADU is one of the smartest ways to turn your property into a revenue generator. In Lewiston, where rental demand is strong due to Lewis-Clark State College and limited housing options, a well-designed ADU can rent for $800–$1,200 per month, creating an annual income of $9,600–$14,400. That’s enough to offset a mortgage or fund future home improvements. Under Ordinance No. 4755, ADUs are allowed on lots 5,000 sq. ft. or larger, and Jason ensures every design meets code while blending seamlessly with your home—so you attract quality tenants and maintain property value.

  • Aging in Place

    ADUs offer a practical solution for families who want to keep loved ones close without sacrificing independence. Instead of costly assisted living, an ADU provides a private, accessible space for aging parents or relatives, complete with features like zero-step entries and wide doorways. Regional surveys show 25% of residents want ADUs for elderly family care, making this one of the most requested uses in the LC Valley. Collom Construction incorporates universal design principles and energy-efficient materials, creating spaces that are safe, comfortable, and sustainable for years to come.

  • Home Office

    Remote work is here to stay, and an ADU gives you the dedicated workspace you need without compromising family space. Imagine a quiet, professional environment with natural light, custom storage, and high-quality finishes—all steps from your door. Lewiston’s ordinance allows attached or detached ADUs, so you can choose a design that fits your lot and lifestyle. Collom Construction uses premium materials like Pella windows and advanced insulation to create a productive, energy-efficient workspace that feels like an extension of your home, not an afterthought.

  • Family Expansion

    When your family grows or you need space for guests, an ADU adds flexibility without the stress of moving. For example, Lewiston City code allows ADUs up to 30% of your main home’s habitable floor area (never exceeding 900 sq. ft.), giving you plenty of room for a functional layout. Jason specializes in designs that complement your existing structure, from roof pitch for snow load to matching exterior finishes, ensuring your addition looks intentional and elevates your property value. It’s the perfect way to create more space while preserving the character of your home.

An aerial view of a river flowing through a town with a bridge, surrounded by fields and hills, during sunset.

ADU Rules Made Simple

Building an ADU in our region is simpler than you might think. Under Lewiston’s Ordinance No. 4755, homeowners can add an accessory dwelling unit on any residential lot over 5,000 sq. ft., provided it meets a few straightforward requirements: a maximum size of 600-900 sq. ft., up to two bedrooms, one additional off-street parking space, and a design that complements your primary home. Height limits are 18 ft for single-story and 28 ft for two-story units, ensuring your ADU fits the neighborhood character. Nearby Moscow has embraced ADUs as part of its housing strategy, with public input showing strong support for flexible, affordable living options. And because we’re licensed in Washington, Jason can also guide you through planning in Asotin County and Whitman County, where he has established relationships with local officials. Wherever you live in the LC Valley or Palouse, we make navigating codes and permits stress-free—so you can focus on creating the space you need.

Watercolor painting of a backyard with a small cream-colored house, a fire pit with chairs, a patio table with an umbrella, surrounded by green plants and trees, with mountains in the background.

Custom Design or Pre-Approved Plans—Your Choice

We don’t do cookie-cutter, but we understand that simplicity matters. Every ADU we build is tailored to your property and lifestyle—whether converting an attic, finishing a basement, or creating a detached unit that looks like it belongs. Jason is proficient in professional drafting software, so your custom plans start with precision and compliance. Prefer a faster route? We can also work with the pre-approved ADU plans adopted by the City of Lewiston, giving you a streamlined option without sacrificing quality. No matter which path you choose, we prioritize healthy homes designed for our region’s microclimates—built to stand the test of time.

Learn More About pre-approved ADU plans

Financing Your ADU

Adding an Accessory Dwelling Unit (ADU) is an investment that pays off. Whether you’re creating rental income, housing family, or adding property value, financing options make it easier than ever.

Home Equity Lines of Credit (HELOC): Tap into your home’s equity for flexible funding.
Construction Loans: ICCU offers competitive rates for ADU builds.
Local Credit Unions: Personalized service and community-focused lending.
Rental Income Potential: Offset your loan with monthly rental income from your ADU.

Housing challenges in our region aren’t abstract—they’re real, and they affect families every day. Lewiston and the Palouse face rising demand for affordable housing, limited inventory, and growing pressure to preserve neighborhood character. ADUs offer a smart solution: they help address housing shortages, reduce sprawl, and keep families close—all without sacrificing the integrity of our communities. For Jason, this isn’t just construction; it’s problem-solving at its highest level. His mission is to create homes that meet today’s needs while preparing for tomorrow’s challenges, because healthy, sustainable housing is the foundation of a thriving region.

Lewiston and the Palouse Need ADUs

Infographic displaying percentages of support for ADUs, plans to use ADUs for rental income, and for elderly family care.

ADUs aren’t just an option—they’re a solution.

Building solutions where they are needed the most.

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“Every home we build solves a problem—and strengthens the community.”

- Jason Collom