ADU/DADU Construction | Seattle
Rabbit Residential handles Seattle ADU construction for homeowners who need more from their property than it’s currently giving them. An ADU isn’t just extra square footage. It’s a fully permitted residence built on the same lot as your main house, reviewed and inspected under Seattle code.
What Seattle Accessory Dwelling Unit (ADU) Construction Includes
- Site feasibility review on your Seattle property
- Zoning and land use analysis
- Architectural floor plan development
- Engineering coordination
- Full permitting process management
- Foundation and structural construction
- Mechanical, electrical, and plumbing systems
- Interior buildout including kitchen and bathroom
- Final inspections and documentation
Seattle allows both Attached Accessory Dwelling Units and Detached Accessory Dwelling Units in most residential zones. In many cases, current law also allows ADU/DADU combinations on the same property, subject to lot coverage and height restrictions.
Before we design anything, we confirm what the city will permit on your site. That protects your budget and your timeline.
Real Seattle Conditions That Shape Your Project
Seattle is not uniform. Your block matters.
In neighborhoods with alley access, a Backyard Cottage can often be positioned to maintain privacy while allowing practical construction access. In hillside areas of West Seattle, foundation design and drainage control are central to approval. For properties near environmentally critical areas, additional reports may be required before permits are issued.
Seattle’s updated rules have expanded options for Accessory Dwelling Units, but they didn’t remove oversight. Square footage limits, setbacks, tree protection requirements, and inspection sequencing still apply.
When a homeowner wants to build an ADU for family or rental income, we test that plan against Seattle land use standards before anything else. Good intentions still need to survive the permit process.
Let’s Talk About Your Project
Whether you’re planning a custom home, addition, or remodel, we’ll help you understand what’s possible and what it takes to get there.
No pressure. Just a conversation.
Attached ADUs and Backyard Cottages
Seattle homeowners typically choose between two paths.
An Attached ADU connects directly to the main house. This might involve converting existing space such as a basement or garage, or building an addition with a private entrance. An Attached ADU works well when you want family close but still independent.
A Detached ADU, often called a Backyard Cottage or Seattle DADU, stands separately in the backyard. A Detached Accessory Dwelling Unit puts real physical separation between the main house and the new living space. Many homeowners choose this path when rental income or multigenerational privacy is the priority.
Both options create more living space without purchasing new land. Both must comply with Seattle permitting and inspection requirements.
A well-built Detached ADU should feel like a small home, not a temporary structure tucked behind the house.
Our Construction Process
Site and Zoning Confirmation
We visit your property and confirm setbacks, allowable square footage, height limits, and land use constraints. If the site includes environmentally critical areas, that review happens early.
Design and Permits
Our team develops the architectural floor plan and coordinates engineering. We manage the full permitting process with the city. Correction notices are handled by our team, not passed along to you.
Preconstruction Alignment
Before building begins, we finalize scope, materials, systems, and schedule. You know what's being built and how it will perform long-term.
Field Oversight
A dedicated superintendent manages daily construction activity. Inspections are scheduled in sequence. Structural framing, energy compliance, and life safety items are reviewed as required by Seattle code. When you invest at this level, standards aren't assumed. They're enforced.
Completion
Final inspections are completed. Documentation is organized. The ADU is delivered as a legal, inspected residence on your property.
Why Management Structure Matters
Many homeowners talk with multiple ADU contractors before deciding. The risk in Seattle isn’t only cost. It’s fragmentation.
When design, permits, and construction are handled by separate parties, accountability gets murky the moment a city correction is issued or a site condition shifts. Everyone points somewhere else.
Rabbit Residential operates as one construction company with centralized oversight.
- One contract
- One accountable ADU builder
- One coordinated construction process
That structure protects your project when city regulations and real-life conditions collide.
Homeowners build Accessory Dwelling Units for specific reasons. A parent needs proximity without sharing the main house. Rental income becomes part of long-term financial planning. A home office requires real separation from daily household life.
Those are practical, human decisions. They deserve disciplined execution.
Ready to Build? Let's Talk.
Rabbit Residential handles Seattle ADU construction from zoning review through final inspection, all under one contract and one team. No handoffs, no finger-pointing, no surprises about who owns what.
If you’re serious about adding a Backyard Cottage, Attached ADU, or Detached Accessory Dwelling Unit to your Seattle property, let’s start with a site conversation. We’ll tell you exactly what’s possible and what the process looks like before you’ve committed to anything.
Call us or submit your project details online. We’ll take it from there.
FAQs – ADU Construction Seattle
How long does the Seattle permitting process take for an ADU?
The permitting process typically spans several months depending on project complexity and city review timelines. Getting zoning confirmed early is one of the best ways to reduce delays down the line.
Can I build both an Attached ADU and a Detached ADU on my property?
In many Seattle zones, yes. Current law allows multiple Accessory Dwelling Units on the same property, subject to square footage and setback limits.