Top 10 Questions to Ask Your Seattle ADU Architect Before Building

Accessory Dwelling Units (ADUs) are becoming a key part of the housing solution in Seattle, offering flexible living options for homeowners, tenants, and extended families. With property values climbing and urban space becoming increasingly limited, an ADU can provide much-needed space and additional income while enhancing the value of your property. However, the design and permitting process can be overwhelming without the right guidance. That’s where an experienced Seattle ADU architect comes in. To make the most of your investment and avoid costly pitfalls, it’s essential to ask the right questions before you begin. Here are the top 10 questions to ask your ADU architect to ensure a smooth, informed process from concept to completion.

1. Are You Familiar with Seattle’s Zoning and ADU Regulations?

Seattle has specific zoning codes that govern ADU placement, size, and design. From rear setbacks to height restrictions and lot size requirements, the rules can be nuanced and vary depending on your neighborhood and lot configuration. A qualified Seattle ADU architect should be well-versed in these details and able to advise you on what’s feasible for your specific property. Ask if they’ve worked within Seattle’s Residential Small Lot (RSL) or Lowrise (LR) zones and how they handle updates to the Seattle Municipal Code that may affect your project.

2. How Many ADUs Have You Designed in Seattle?

Experience with ADUs in Seattle is invaluable. The more local ADUs your architect has completed, the more insight they will have into potential red flags, timeline delays, and design opportunities. Look for case studies, testimonials, or photos of completed ADU projects in Seattle neighborhoods. This not only assures you of their expertise but also provides design inspiration for your own project. Ask how many of their designs have been permitted and built successfully in the last 2-3 years under current city regulations.

3. What Is Your Design Philosophy for Small Spaces?

Designing for small square footage requires a unique skill set. A great ADU design should make the space feel open, functional, and aesthetically pleasing. Your architect should prioritize multi-purpose features, open floor plans, natural lighting, and smart storage solutions. Ask if they can show you examples of how they’ve maximized usability in 400–800 square-foot ADUs. Their philosophy should align with your goals—whether you’re building a rental unit, a home office, or a space for aging parents.

4. Can You Help with Permitting and Code Compliance?

The permitting process in Seattle can be rigorous. A seasoned Seattle ADU architect should offer comprehensive support for the permitting process, including preparation of submittals for the Seattle Department of Construction & Inspections (SDCI). Ask how they handle communication with city planners and whether they provide site plans, floor plans, elevations, and code documentation as part of their standard service. Some architects even offer permit expediting, which can shave weeks off your project timeline.

5. Do You Offer Sustainable or Green Building Options?

Seattle homeowners increasingly seek sustainable solutions in their construction projects. Whether it’s incorporating passive solar design, low-VOC materials, advanced insulation, or water-efficient plumbing, your architect should offer options that reduce environmental impact and operating costs. Ask if they have experience with Built Green certification or similar green building standards. Sustainable ADUs not only appeal to environmentally conscious renters but also contribute to long-term value and comfort.

6. Can You Show Me a Portfolio of Completed Seattle ADUs?

A visual portfolio speaks volumes about an architect’s capability, attention to detail, and style. Look for diversity in design—urban, modern, traditional—to gauge how well they can adapt to different homeowner visions. Be sure to ask for before-and-after photos, floor plans, and even 3D renderings if available. Bonus points if they provide access to physical walkthroughs of completed projects or detailed video tours to illustrate spatial flow and finish quality.

7. How Do You Handle Project Budgeting and Cost Estimation?

Staying on budget is one of the top concerns for Seattle homeowners embarking on an ADU project. A skilled architect should help you establish a realistic budget and provide detailed cost estimates that include everything from design fees to construction costs and permit fees. Ask how they account for cost contingencies and what happens if estimates shift during the design or construction phases. A transparent process with phased budgeting milestones can help you plan more confidently.

8. What’s Your Process from Initial Concept to Construction?

Understanding your architect’s workflow ensures that you’ll be aligned every step of the way. Typically, the process involves several stages: site evaluation, schematic design, design development, construction documentation, permitting, and construction oversight. Ask about timelines for each phase and what deliverables you’ll receive. Do they conduct site visits during construction? Will they coordinate with engineers or landscape designers? A full-service architect will offer seamless coordination from start to finish.

9. Do You Work With Contractors or Recommend Builders?

Finding a reputable builder is just as important as hiring the right architect. Ask if the architect collaborates with a network of vetted contractors who specialize in ADUs. Having a strong architect-contractor relationship can streamline construction, improve communication, and reduce delays. Some firms offer design-build services in-house, while others maintain preferred partnerships. Either way, ask if they’ll help you review bids, check licenses and references, and stay involved during construction oversight.

10. How Will You Keep Me Involved Throughout the Process?

Client-architect communication is vital to a successful project. Ask how the architect will keep you informed and engaged—will there be regular meetings, video calls, or shared project management platforms? Will you have input at each design milestone? You want a collaborative partner who welcomes your feedback and ensures your vision is reflected in the final design. Consistent communication minimizes misunderstandings and ensures a smooth experience from beginning to end.

Conclusion

Your ADU project is a major investment—not only financially but also in terms of your living experience and property value. Asking these 10 essential questions will help you evaluate whether a Seattle ADU architect has the local knowledge, design expertise, and client-first approach you need. At Coates Design, we specialize in innovative, sustainable, and client-focused ADU projects throughout the Seattle area. Reach out today for a personalized consultation and let’s bring your vision to life.