Custom ADU Builders in Whatcom County
More room for family. Right where you are.
Serving Whatcom County, WA
Whether you’re making space for aging parents, giving adult children a home of their own, or planning for your family’s future, OSHN Designs partners with you to create thoughtful, well-crafted ADUs in Whatcom County.
Thoughtful ADUs. Built around the way you live.
Every family is different, and every property has its own possibilities. We collaborate closely with you to understand your goals and create a custom space that balances beauty, function, and long-term comfort.
A Home for
Aging Parents
Keep parents close, with a comfortable space designed around privacy, independence, and everyday connection.
A Home for
Adult Children
Make room for the next chapter with a separate living space and family support nearby.
A Home for
Changing Family Needs
Plan a flexible home that can support your family today and adapt as priorities change.
Building ADUs Across Whatcom County
From Bellingham to the surrounding communities, we help homeowners explore what’s possible on their properties. Each location has its own considerations, and we’re here to guide you through the process.
Is an ADU possible on your property?
What’s possible depends on your property’s location, applicable regulations, access, utilities, and site conditions. Requirements can differ between cities and unincorporated Whatcom County.
We take time to understand your goals and help you explore the considerations involved in planning and building your ADU.
The OSHN Approach
Relationship first.
Every step of the way.
Choosing an ADU designer and builder is about more than a floor plan. OSHN brings planning, design, permitting, and construction into one collaborative relationship, with clear guidance for your property and your family’s goals.
✓ Relationship First
A thoughtful home starts with listening.
✓ Clear Communication
Clear guidance, from planning and permitting through construction.
✓ Quality
Careful craftsmanship. Beautiful, functional spaces built to last.
“They took the time to explain the entire process clearly, which made everything feel smooth and stress-free.”
Tannis Peura
Google review · ★★★★★
A Clear Path Forward
Your ADU design-build process.
1.
Book a 20-minute consultation.
Tell us about your family and the space you’re imagining.
2.
Explore your property & goals.
Consider access, utilities, site conditions, and the questions that need answers.
3.
Plan and design together.
Shape the layout, scope, and details around your priorities.
4.
Build with care.
Bring the plans to life through thoughtful craftsmanship and clear communication.
Whatcom County ADU FAQs
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It depends on where your property is located and the requirements that apply to it. Properties within city limits may follow different rules than those in unincorporated Whatcom County. Zoning, utilities, access, and site conditions can also influence what's possible. We can help you explore the next steps for your property.
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Every ADU is different. Costs depend on the size, design, site conditions, utility connections, and finishes you choose. We start by learning about your goals and budget so we can help you understand the considerations involved in creating a space that works for your family.
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Absolutely. Many families explore ADUs as a way to keep aging parents close while preserving their privacy and independence. We can work with you to consider comfortable layouts, accessibility features, and thoughtful design details that support everyday living.
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Yes. As a design-build firm, we guide clients through planning, design, permitting, and construction. We'll talk through the services your project needs and help you understand the process before moving forward.
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OSHN Designs works with homeowners in Bellingham and surrounding Whatcom County communities. If you're wondering whether your property is within our service area, we'd love to hear from you.
Build for today. Think in generations.
What do you want to leave for your kids?
An ADU can be more than a solution for right now. It’s a way to put the land and resources you have today toward something lasting: a home for family, more choices for your children, and the potential to build generational wealth. At OSHN, we help you explore what you can build with the next generation in mind.
Thinking about keeping land in the family through a trust? Talk with an estate-planning attorney and financial adviser about ownership, taxes, and inheritance. OSHN’s role is to help you plan, design, and build the home; property value and financial returns are not guaranteed.