DADU Construction in Seattle
A Detached ADU is one of the most consequential investments a Seattle homeowner can make. It is a separate structure, on the same lot as your main home, built to function as an independent dwelling. Rental income, multi-generational living, home office, or guest space. Done right, it is a thirty-year asset. Done wrong, it is six figures of regret.
We design and build DADUs across Seattle with in-house architectural design, structural engineering, SDCI permitting, and construction. One team, one timeline, one point of accountability.
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Seattle DADU Rules at a Glance
The current Seattle DADU rules, accurate as of 2026.
There is no minimum lot size requirement for a DADU if the proposed unit is at least 1,000 square feet. Setbacks are usually the binding constraint, particularly on tighter urban lots in neighborhoods like Ballard, Wallingford, and Beacon Hill. Tree protection ordinances can also shape what is buildable, especially on lots with mature exceptional trees.For the official source, see theSeattle SDCI ADU page
contact usWhat Is a DADU?
A Detached Accessory Dwelling Unit, commonly called a DADU or a backyard cottage, is a separate residential structure built on the same lot as a primary home. It has its own kitchen, bathroom, sleeping area, and entrance. In Seattle, a DADU can be up to 1,000 square feet, can be one or two stories, and can be rented out as a long-term rental without owner-occupancy requirements.
DADUs are different from attached ADUs (which share a wall with the main home) and from conversions (which repurpose existing garage or basement space). A DADU is a brand-new structure with its own foundation, its own utility hookups, and its own legal address.
In 2026, DADUs are the fastest-growing category of Seattle residential construction. The shift started with Washington State's HB 1337, which removed owner-occupancy requirements statewide, allowed up to two ADUs per residential lot, and prevented cities from capping ADU sizes below 1,000 square feet. Combined with continued Seattle housing demand, the legal landscape now favors DADU construction more than it has in decades.
Flexible Payment Plans in Bellevue
We make home renovations affordable with financing options that fit your budget, from small projects under $100k to major renovations over $100k. Start your project now!
New Room Addition Contractors Creating Stunning Additions
Home Addition Ideas – Inspiring Ways to Expand Your Space
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How We Make Bellevue Remodeling Easy
A Simple, Stress-Free Remodel Journey
Request an Initial Consultation
In person Consultation
Pre-construction Agreement
Construction Phase
Final Walkthrough & Warranty
Real Feedback, Real Transformations
Our Clients Love Their Home Remodels
Nothing speaks louder than real results. Our clients love the transformations we help bring to life, and their feedback reflects the quality, care, and craftsmanship behind every project. From home remodels to custom builds, see why homeowners trust Brutsky Builds to turn their vision into reality.
Irina S, on Yelp
Love working with Brutsky Builds kitchen and bathroom remodeling! They take immediate massive action and get things done. They did a lot of pre construction planning so that there was always work going on our project. They completed everything on time and excellent quality.
Kyla Regan, GOOGLE REVIEWS
We hired Brutsky Builds to help us build the Primary bathroom of our dreams. We required extensive repairs due to water damage in the space, and Erik's Team tackled it all. They guys replumbed the space, installed a new dedicated hot water heater, installed drywall, a new shower, new tub, new vanity, etc. Our Primary bathroom looks fantastic! Erik's team is professional, knowledgeable, talented, and courteous. They came in when we needed Professional help and worked their magic. We are incredibly pleased and very grateful.
Sunyoung H, GOOGLE
We recently finished an amazing master bathroom remodel with Brutsky Builds. Erik, Filip, and his crew are dedicated, professional, and dependable. During the initial planning meeting, they provided a useful tool to help us plan out the remodel and keep the project on track. Filip was a great project manager who provided daily updates with pictures and was super responsive to all my concerns and questions. The paid attention to every detail, ensuring everything was perfect. The entire process was smooth, and the final result is a beautiful and functional space we absolutely love. Don't let their seeming 'youth' fool you- These guys know what they're doing! We highly recommend Brutsky Builds for any home renovation projects.
Vadim P, on Yelp
Since we had little experience in construction, we were very hesitant to take on a big full home remodeling project. Especially after hearing so many horror stories from other's. So we were carefully interviewing and choosing a contractor. We chose Erik's team at Brutsky Builds because of their honesty and ease of communication and flexibility we saw. These guys/gals are truly dedicated to excellence and clearly passionate for their work (every member on the team). We had an incredible experience remodeling our home with Brutsky Builds.
Kelly A, Facebook
4. Brutsky Builds recently completed our kitchen remodel and they exceeded our expectations. This is our third remodel on our 1955 mid-century home - first with Brutsky Builds - and this was our easiest and smoothest remodel.
The team did a complete demo of our kitchen, taking it down to the studs. From there, they patched our original wood flooring, tore down a wall and an archway, did new insulation, dry walled, relocated most appliances, shifted our heating vent, hung (heavy) floating shelves, and then did the electrical, plumbing, cabinets, countertops, and tile.
All of this was completed in just 30 days. It was wild. And it’s GORGEOUS!! Everything turned out beautiful and we couldn’t be happier.
Matt B, GOOGLE
We had a challenging little project that Brutsky Builds made simple! We had a floating shelf made for between two cabinets in our bathroom, but our previous contractor made errors in the measurements, and it was the wrong size. After we moved on from him, Brutsky was willing to measure and recut the marble and then install it, for a reasonable price. Very pleased.
FAQs About Home Additions in Bellevue
Please feel free to call. But here are some frequently asked questions we get.
The size of your home remodeling addition in Bellevue depends on factors like lot size, zoning regulations, and existing structures. Generally, home additions must comply with setback requirements, height limits, and lot coverage rules set by the city.
For example:
Lot coverage limits determine how much of your land can be covered by buildings.
Setback rules require a certain distance between your addition and property lines.
Height restrictions may apply, especially for second-story additions.
Our team of home additions contractors ensures your expansion meets all local codes while maximizing your available space. Need guidance? Let us help you design an addition that fits your needs and follows Bellevue’s regulations!
A home remodeling addition gives you extra space without the hassle of moving. It can increase your home’s value, improve functionality, and create more room for family or rental income. Plus, working with local contractors for home additions ensures the new space blends seamlessly with your existing home.
Yes, home additions require permits to ensure they meet Bellevue’s building codes and zoning regulations. The city has specific guidelines on setbacks, lot coverage, height limits, and structural safety that must be followed.
We, home additions contractors, handle the entire permitting process, ensuring your project stays compliant with local regulations. For more details on Bellevue’s zoning laws and permit requirements, you can check:
Bellevue Building Permit Information: https://bellevuewa.gov/city-government/departments/development/permits
Zoning Regulations & Land Use Code: https://bellevuewa.gov/city-government/departments/development/codes-and-guidelines
We take care of the paperwork, inspections, and approvals so you don’t have to stress. Let’s get your home addition started the right way!
Absolutely! Our team ensures your new space integrates seamlessly with your home’s current layout, materials, and architectural style. The goal is to make it look like the addition was always part of your home.
Look for home additions contractors with experience, positive reviews, and a clear process. At Brutsky Builds, we offer transparent pricing, quality craftsmanship, and a stress-free experience, making sure your home addition is built on time and within budget.
Get DADU Feasibility for Your Lot
A DADU is too consequential a project to start without knowing whether your lot can actually support one. We will visit your property, evaluate setbacks against your goals, locate existing utilities, assess tree protection and site access, and give you a written feasibility report before you commit a dollar to design.
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