ADU Architect

The ADU architect.

A black and white image of a custom home residence

At Refine Design Architecture, we are your starting point for any accessory dwelling unit project—guiding you from initial concept through construction completion. As licensed ADU architects in Washington, we collaborate closely to craft thoughtful secondary dwellings that meet local permitting requirements while maximizing livability in compact spaces. Our work goes beyond drawings: we choreograph light, views, and circulation to create memorable architectural moments that make these smaller homes feel spacious and welcoming. Through high-caliber design, detailed documentation, and personalized service, we shape ADU spaces that enhance your property value and provide meaningful homes for generations.

Meet our Residential Architect Team

What can we do for you?

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01. Pre-Design

This is where we get on a first name basis. Our ADU architects collaborate with you to understand your project vision and goals while verifying zoning requirements and feasibility for your accessory dwelling unit.

02. Design

This is the good stuff. With your ideas and our ADU design expertise, our team puts together several design options that maximize every square foot while exploring floor plans and 3D renderings of your accessory dwelling unit.

03. Permits

At this point, your ADU design is ready for submission to your local jurisdiction to obtain necessary building permits. We can lead this effort or assist you in navigating the permitting process.

04. Construction

Finally, we provide you with construction drawings detailed to a level that can be given to a general contractor to start building your ADU project. We can help vet builders and coordinate during construction to keep everything aligned.

Don't just take our word for it.

Here's what our clients have to say.

"RD's team provided us with a very special creative process designing our home...If you are seriously looking to elevate your next project, work with Refine Design!"

Shy F.

Mountain Lodge

"Stone and Julia were very professional and extremely helpful in designing our project. Their patience and attention to detail were integral in configuring a change of use building."

Dustin D.

Ballard DADU

"They not only helped bring our vision to life, but offered a point of view we had not thought of. I highly recommend this duo - they are incredibly easy to work with."

Kendall F.

Gig Harbor Remodel

"No words can describe how exceptional Julia and Stone are at their work...Not only did they research extensively into the building codes but they poured so much thought into the design."

Yu Chi S.

Seattle Bathroom Remodel

"It was great working with Refine Design Architecture for our cabin expansion. They listened to our requirements, offered feedback and produced designs that fulfilled our vision"

Antonio G.

Leavenworth Cabin Addition

"Their work was on schedule, on budget, and their ideas were very helpful. If you're searching for an architectural team that can fit the bill, look no further."

James M.

Accessibility Retrofit

Have questions?
We have answers.

At Refine Design Architecture, we believe that designing an accessory dwelling unit isn't a "one size fits all" process.

What is the ADU design process?

The ADU process follows a clear path: initial consultation and feasibility study → schematic design and design development → permit documentation → construction support. We begin by understanding your goals and site constraints, then develop design options that maximize functionality within ADU regulations. Once the design is refined, we prepare permit drawings and guide you through approvals. Throughout construction, we provide support to ensure your vision becomes reality.

Do I need an architect for my ADU?

In Washington State, an architect isn't always legally required for ADU projects, but it's highly recommended for most situations. ADU regulations are complex and vary by jurisdiction, making professional guidance valuable for compliance and design optimization. An experienced ADU architect can navigate zoning requirements, maximize space efficiency, and ensure your project meets all building codes. We help you avoid costly mistakes while creating a thoughtfully designed space that adds real value to your property.

What does ADU construction cost?

ADU construction costs vary widely based on size, complexity, site conditions, and finish level. Factors include whether you're building new construction, converting existing space, or adding above a garage. Site accessibility, utility connections, and local construction costs also impact the budget. Material choices and design complexity further influence final costs. We work with you during design to make informed decisions that align with your budget and goals.

How long does an ADU project take?

ADU projects typically require 2-4 months for design and permit approval, depending on design complexity and local jurisdiction review times. Construction timelines range from 4-12 months based on project scope and contractor availability. Detached new construction generally takes longer than conversion projects. We help streamline the process by preparing thorough permit documents and coordinating with experienced contractors familiar with ADU construction requirements.

How much does an ADU architect cost?

ADU architect fees typically range from 10-15% of construction cost, though we also offer fixed-fee arrangements for certain project types. Our comprehensive services include feasibility studies, design development, permit drawings, and construction support. The investment in professional design often pays for itself through optimized space planning, smoother permitting, and avoided construction issues. We provide transparent fee structures and work within your budget to deliver maximum value for your ADU project.

Why hire an architect for your ADU?

An ADU architect brings specialized expertise in navigating complex zoning requirements while maximizing limited space through thoughtful design. We understand how to create functional, comfortable homes within ADU constraints, optimizing natural light and circulation. Our experience with local permitting processes helps avoid delays and costly revisions. Beyond compliance, we design spaces that feel like home—not just additional square footage—creating lasting value for your property and meaningful living spaces.